Vector PRO Manual for SI-TEX PDF 4-07 - Hodges Marinecdnstatic.hodgesmarine.com/productmanuals/SITVECTORPRO-15.pdf · • DGPS service provider performance specifications. ... 1.7

Vector PRO / Lite Reference Manual

Part Number 875-0076-001-R Date: April 6, 2005

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Copyright Notice © Copyright 2004 CSI Wireless Inc. All rights reserved. No part of this manual may be stored in a retrieval system, transmitted, or reproduced by any means, including, but not limited to photocopy, photograph, digitizing, or otherwise, without the prior written permission from CSI Wireless Inc.

Trademarks The CSI Wireless logo and COAST™ are trademarks of CSI Wireless Inc. All other trademarks are the property of their respective owners.

FCC Notice This device complies with Part 15 of the FCC Rules. Operation is subject to the following two conditions.

(1) this device may not cause harmful interference, and

(2) this device must accept any interference received, including interference that may cause undesired operation.

CSI Wireless Inc. 4110 9th Street SE Calgary, Alberta, Canada T2G 3C4 Telephone number: +1-403-259-3311 Fax number: +1-403-259-8866 E-mail address: [email protected] Web Site: www.csi-wireless.com

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CSI Wireless Limited Warranty CSI Wireless Inc. (“CSI”) hereby warrants solely to the end purchaser of the Products, subject to the exclusions and procedures set forth herein below, that the Products sold to such end purchaser shall be free, under normal use and maintenance, from defects in material and workmanship for a period of 12 months from delivery to such end purchaser. Repairs and replacement components are warranted, subject to the exclusions and procedures set forth below, to be free, under normal use and maintenance, from defects in material and workmanship for 90 days from performance or delivery, or for the balance of the original warranty period, whichever is greater.

Purchaser’s Exclusive Remedy The end purchaser’s exclusive remedy under this warranty shall be limited to the repair or replacement, at the option of CSI Wireless, of any defective Products or components thereof. The end user shall notify CSI Wireless or a CSI Wireless approved service center immediately of any claimed defect. Repairs shall be made through a CSI Wireless approved service center only.

Exclusions CSI Wireless does not warrant damage occurring in transit or due to misuse, abuse, improper installation, neglect, lightning (or other electrical discharge) or fresh/salt water immersion of Products. Repair, modification or service of CSI Wireless products by any party other than a CSI Wireless approved service center shall render this warranty null and void. CSI Wireless does not warrant claims asserted after the end of the warranty period. CSI Wireless does not warrant or guarantee the precision or accuracy of positions obtained when using Products. Products are not intended for primary navigation or for use in safety of life applications. The potential accuracy of Products as stated in CSI

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Wireless literature and/or Product specifications serves to provide only an estimate of achievable accuracy based on:

• Specifications provided by the US Department of Defense for GPS Positioning, • GPS OEM Receiver specifications of the appropriate manufacturer (if applicable), and • DGPS service provider performance specifications. CSI Wireless reserves the right to modify Products without any obligation to notify, supply or install any improvements or alterations to existing Products.

No Other Warranties THE FOREGOING WARRANTY IS EXCLUSIVE OF ALL OTHER WARRANTIES, WHETHER WRITTEN, ORAL, IMPLIED OR ARISING BY STATUTE, COURSE OF DEALING OR TRADE USAGE, IN CONNECTION WITH THE DESIGN, SALE, INSTALLATION, SERVICE OR USE OF ANY PRODUCTS OR ANY COMPONENTS THEREOF, INCLUDING, BUT NOT LIMITED TO, ANY WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.

Limitation of Liability THE EXTENT OF CSI WIRELESS’S LIABILITY FOR DAMAGES OF ANY NATURE TO THE END PURCHASER OR ANY OTHER PERSON OR ENTITY WHETHER IN CONTRACT OR TORT AND WHETHER TO PERSONS OR PROPERTY SHALL IN NO CASE EXCEED, IN THE AGGREGATE, THE COST OF CORRECTING THE DEFECT IN THE PRODUCT OR, AT CSI WIRELESS’S OPTION, THE COST OF REPLACING THE DEFECTIVE ITEM. IN NO EVENT WILL CSI WIRELESS BE LIABLE FOR ANY LOSS OF PRODUCTION, LOSS OF PROFITS, LOSS OF USE OR FOR ANY SPECIAL, INDIRECT, INCIDENTAL, CONSEQUENTIAL OR CONTINGENT DAMAGES, EVEN IF CSI WIRELESS HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. WITHOUT LIMITING THE FOREGOING, CSI

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WIRELESS SHALL NOT BE LIABLE FOR ANY DAMAGES OF ANY KIND RESULTING FROM INSTALLATION, USE, QUALITY, PERFORMANCE OR ACCURACY OF ANY PRODUCTS.

Governing Legislation To the greatest extent possible, this warranty shall be governed by the laws of the State of Arizona. In the event that any provision hereof is held to be invalid by a court of competent jurisdiction, such provision shall be severed from this warranty and the remaining provisions shall remain in full force and effect.

Obtaining Warranty Service In order to obtain warranty service, the end purchaser must bring the Product to a CSI Wireless approved dealer, along with the end purchaser’s proof of purchase. For any questions regarding warranty service or to obtain information regarding the location of any of CSI Wireless’s dealers, contact CSI Wireless at the following address.

CSI Wireless Inc. 4110 9th Street SE Calgary AB, T2G 3C4 Canada Telephone number: +1-403-259-3311 Fax number: +1-403-259-8866 E-mail address: [email protected]

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Table of Contents List of Figures..........................................................................................xiv List of Tables ...........................................................................................xvi Preface................................................................................................. xviii

Organization.................................................................................... xix Customer Service ............................................................................ xxi World Wide Web Site ......................................................................xxii Document Conventions.....................................................................xxii Notes, Cautions, and Warnings.........................................................xxii

1. Quick Start ................................................................................... 23 1.1 Receiving Your Shipment ........................................................... 24 1.2 Unpacking Your Vector PRO System ......................................... 24 1.3 Vector PRO Interface ................................................................ 25 1.4 Understanding the Vector PRO .................................................. 25

1.4.1 Moving Base Station RTK................................................. 26 1.4.2 Supplemental Sensors - Reduced Search Time.................. 27 1.4.3 Supplemental Sensors - Heading System Backup.............. 27

1.5 Installation Overview .................................................................. 28 1.6 Mounting Configurations and Offset Settings................................ 29 1.7 Gyro Initialization Process ......................................................... 30 1.8 NMEA 0183 Message Interface.................................................. 31

1.8.1 Tilt Aiding ....................................................................... 31 1.8.2 Tilt Sensor Calibration...................................................... 31 1.8.3 Magnetic Aiding .............................................................. 32 1.8.4 Magnetometer Calibration................................................. 33

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1.8.5 Gyro Aiding .................................................................... 34 1.8.6 Time Constants............................................................... 35 1.8.7 Level Operation ............................................................... 40 1.8.8 Heading Compensation.................................................... 40 1.8.9 Configuring for Pitch or Roll .............................................. 41 1.8.10 Configuring Negative Pitch or Roll ..................................... 42 1.8.11 Pitch / Roll Compensation................................................ 42 1.8.12 Forcing a New RTK Search.............................................. 43 1.8.13 Summary Command........................................................ 43 1.8.14 HELP command.............................................................. 43 1.8.15 $HEHDT Message........................................................... 44 1.8.16 $HEROT Message .......................................................... 45 1.8.17 Proprietary $PSAT,INTLT Message................................... 45 1.8.18 Proprietary $PSAT,HPR Message .................................... 45

2. Installation.................................................................................... 47 2.1 System Parts List..................................................................... 47 2.2 Installation Overview.................................................................. 47

2.2.1 Fixed Base Installation .................................................... 47 2.2.2 Pole-mounting Base Installation........................................ 48

2.3 Vector PRO Interface................................................................ 49 2.4 Choosing a Mounting Location ................................................... 49

2.4.1 GPS Reception............................................................... 49 2.4.2 Beacon Reception........................................................... 50

2.5 Environmental Considerations .................................................... 51 2.6 Power Considerations ............................................................... 51 2.7 Electrical Isolation .................................................................... 51 2.8 Vector PRO Mounting ............................................................... 52

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2.8.1 Fixed Base Mounting....................................................... 54 2.8.2 Pole and Rail Mounting .................................................... 60 2.8.3 Vector PRO Alignment..................................................... 68

2.9 Routing and Securing the Power / Data Cable.............................. 70 2.10 Interfacing the Vector PRO ........................................................ 70

2.10.1 Power / Data Cable Pin-Out.............................................. 71 2.10.2 Connecting to a power source........................................... 72 2.10.3 Overview of Serial Port Interface........................................ 72 2.10.4 Overview of Serial Port Configuration.................................. 73 2.10.5 Interfacing to a PC Computer............................................ 74 2.10.6 Interfacing to Other Devices .............................................. 76

2.11 Default Parameters ................................................................... 77 3. Vector PRO Overview..................................................................... 80

3.1 GPS ........................................................................................ 80 3.1.1 Satellite Tracking............................................................. 81 3.1.2 Positioning Accuracy....................................................... 81 3.1.3 Update Rates .................................................................. 82

3.2 SBAS ...................................................................................... 82 3.2.1 Automatic Tracking.......................................................... 82 3.2.2 SBAS Performance ......................................................... 83

3.3 Beacon Operation ..................................................................... 84 3.3.1 Tune Modes .................................................................... 84 3.3.2 Receiver Performance...................................................... 86

3.4 COAST™ Technology ............................................................... 86 3.5 Vector PRO Architecture ........................................................... 87

3.5.1 GPS Hardware ................................................................ 87 3.5.2 GPS Firmware ................................................................ 87

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3.5.3 GPS Applications............................................................ 88 3.5.4 Beacon Firmware ............................................................ 88

4. Operation ..................................................................................... 89 4.1 Powering the Vector PRO.......................................................... 89 4.2 Communicating with the Vector PRO.......................................... 89

4.2.1 NMEA 0183 Interface....................................................... 90 4.2.2 Binary Interface............................................................... 91 4.2.3 RTCM SC-104 Protocol.................................................... 91

4.3 Configuring the Vector PRO....................................................... 93 4.4 Configuring the Data Message Output......................................... 93

4.4.1 This Port and the Other Port............................................. 94 5. PocketMAX Utility ......................................................................... 95 6. NMEA 0183 Messages .................................................................. 96

6.1 NMEA Message Elements ........................................................ 96 6.2 PocketMAX.............................................................................. 97 6.3 General Commands .................................................................. 98

6.3.1 $JASC,D1 .....................................................................100 6.3.2 $JAIR............................................................................100 6.3.3 $JASC,VIRTUAL............................................................101 6.3.4 $JALT ...........................................................................102 6.3.5 $JLIMIT .........................................................................103 6.3.6 $JAPP ..........................................................................103 6.3.7 $JBAUD ........................................................................104 6.3.8 $JCONN........................................................................105 6.3.9 $JDIFF ..........................................................................106 6.3.10 $JK...............................................................................106 6.3.11 $JPOS ..........................................................................107

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6.3.12 $JQUERY,GUIDE .......................................................... 107 6.3.13 $JRESET...................................................................... 108 6.3.14 $JSAVE ....................................................................... 108 6.3.15 $JSHOW ...................................................................... 109 6.3.16 $JT............................................................................... 111 6.3.17 $JI................................................................................ 112 6.3.18 $JBIN ........................................................................... 112

6.4 GPS Commands..................................................................... 113 6.4.1 $JASC.......................................................................... 114 6.4.2 $JAGE ......................................................................... 115 6.4.3 $JOFF.......................................................................... 116 6.4.4 $JMASK....................................................................... 116 6.4.5 $J4STRING................................................................... 117 6.4.6 $JSMOOTH .................................................................. 117

6.5 SBAS Commands................................................................... 118 6.5.1 $JWAASPRN................................................................ 119 6.5.2 $JGEO ......................................................................... 120 6.5.3 $JASC,D1..................................................................... 122 6.5.4 $JASC,RTCM................................................................ 122

6.6 Data Messages ...................................................................... 123 6.6.1 GGA Data Message ...................................................... 124 6.6.2 GLL Data Message........................................................ 125 6.6.3 GSA Data Message....................................................... 126 6.6.4 GST Data Message ....................................................... 127 6.6.5 GSV Data Message....................................................... 128 6.6.6 RMC Data Message ...................................................... 129 6.6.7 RRE Data Message....................................................... 130

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6.6.8 VTG Data Message........................................................131 6.6.9 ZDA Data Message ........................................................132 6.6.10 RD1 Data Message ........................................................133 6.6.11 $PCSI,1 Beacon Status Message....................................135 6.6.12 HDT Data Message ........................................................136 6.6.13 ROT Data Message........................................................136 6.6.14 HPR Data Message........................................................136

6.7 Beacon Receiver Commands ....................................................137 6.7.1 $GPMSK Beacon Tune Command...................................137 6.7.2 $PCSI,1 Beacon Status Command ..................................139

6.8 GPS Heading Commands.........................................................139 6.8.1 $JATT,TILTAID...............................................................140 6.8.2 $JATT,TILTCAL..............................................................141 6.8.3 $JATT,MAGAID..............................................................141 6.8.4 $JATT,MAGCAL.............................................................142 6.8.5 $JATT,MAGCLR.............................................................143 6.8.6 $JATT,GYROAID............................................................144 6.8.7 $JATT,LEVEL................................................................145 6.8.8 $JATT,CSEP .................................................................146 6.8.9 $JATT,MSEP.................................................................146 6.8.10 $JATT,HTAU..................................................................147 6.8.11 $JATT,PTAU..................................................................148 6.8.12 $JATT,HRTAU................................................................149 6.8.13 $JATT,COGTAU.............................................................150 6.8.14 $JATT,SPDTAU .............................................................151 6.8.15 $JATT,HBIAS.................................................................152 6.8.16 $JATT,PBIAS.................................................................152

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6.8.17 $JATT,NEGTILT............................................................. 153 6.8.18 $JATT,ROLL ................................................................. 153 6.8.19 $JATT,SEARCH ............................................................ 154 6.8.20 $JATT,SUMMARY ......................................................... 154 6.8.21 $JATT,HELP ................................................................. 156

7. Binary Data................................................................................. 158 7.1 Binary Message Structure ....................................................... 158

7.1.1 Bin 1............................................................................ 160 7.1.2 Bin 2............................................................................ 161 7.1.3 Bin 80 .......................................................................... 162 7.1.4 Bin 93 .......................................................................... 163 7.1.5 Bin 94 .......................................................................... 164 7.1.6 Bin 95 .......................................................................... 165 7.1.7 Bin 96 .......................................................................... 166 7.1.8 Bin 97 .......................................................................... 167 7.1.9 Bin 98 .......................................................................... 168 7.1.10 Bin 99 .......................................................................... 170

8. Frequently Asked Questions ........................................................ 173 8.1 Heading ................................................................................. 173 8.2 General.................................................................................. 173 8.3 Support and Repairs................................................................ 174 8.4 Troubleshooting ...................................................................... 175 8.5 Power, Communication, and Configuration................................. 176 8.6 GPS Reception and Performance............................................. 178 8.7 SBAS Reception and Performance........................................... 178 8.8 Beacon Reception and Performance......................................... 180 8.9 External Corrections................................................................ 181

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8.10 Installation ..............................................................................181 9. Troubleshooting............................................................................183

9.1.1 Radiobeacon DGPS .......................................................208 9.2 DGPS Service Comparison.......................................................210

Appendix A - Specifications .....................................................................185 Appendix B - Interface.............................................................................186 Appendix B – Introduction to GPS, SBAS, and Beacon..............................187 Appendix C – Resources .........................................................................212 Index ..................................................................................................214

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List of Figures Figure 1-1 Vector PRO ............................................................................. 23 Figure 1-2 Cable Interface......................................................................... 25 Figure 2-1 Vector PRO Interface................................................................ 49 Figure 2-2 Vector PRO with Fixed Mount Base........................................... 53 Figure 2-3 Vector PRO with Pole Mount Base ............................................ 53 Figure 2-4 Fixed Mount Base.................................................................... 55 Figure 2-5 Bottom View of Fixed Mount Base............................................. 55 Figure 2-6 Running Cable Through Fixed Base Mount.................................. 56 Figure 2-7 Running Cable Through Fixed Base............................................ 57 Figure 2-8 Power / Data Cable Key and Keyway ......................................... 57 Figure 2-9 Connecting the Power / Data Cable to the Vector PRO ................ 58 Figure 2-10 Fastening the Fixed Base to the Vector PRO............................ 59 Figure 2-11 Fastening the Fixed Base to the Vector PRO............................ 59 Figure 2-12 Threading on the Lock Nut and Washer .................................... 61 Figure 2-13 Running the Cable Through the Pole Base ................................ 62 Figure 2-14 Running the Cable Through the Pole Base ................................ 62 Figure 2-15 Running the Cable Through the Pole Mount ............................... 63 Figure 2-15 Completed Cable Run ............................................................. 63 Figure 2-16 Threading the Pole Base onto the Mount................................... 64 Figure 2-17 Pole Base Threaded onto Mount .............................................. 64 Figure 2-18 Power / Data Cable Key and Keyway ....................................... 65 Figure 2-19 Connected Power / Data Cable ................................................ 66 Figure 2-20 Fastening the Pole Base to the Vector PRO ............................. 67 Figure 2-21 Threading the Lock Nut Against the Pole Base.......................... 67

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Figure 2-22 Locking the Vector PRO once Aligned..................................... 68 Figure 2-23 Lining up the Alignment Sight .................................................. 69 Figure 2-24 Correctly Lined-up Alignment Sight .......................................... 69 Figure 2-25 DB9 Socket Numbering........................................................... 76 Figure 6-1 PocketMAX Screen Capture...................................................... 98 Figure C-1 WAAS Coverage.....................................................................203 Figure C-2 EGNOS Coverage...................................................................204 Figure C-3 Broadcast WAAS Inonspheric Correction Map...........................206 Figure C-4 Extrapolated WAAS Inonspheric Correction Map .......................206 Figure C-5 Broadcast EGNOS Inonspheric Correction Map.........................207 Figure C-6 Extrapolated EGNOS Inonspheric Correction Map .....................207 Figure C-7 World DGPS Radiobeacon Coverage ........................................210

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List of Tables Table 2-1 Power Requirements.................................................................. 51 Table 2-1 Wire Color Interface ................................................................... 71 Table 2-2 Primary GPS Port A DB9 RS-232 Interface.................................. 75 Table 2-3 Secondary GPS Port A DB9 RS-232 Interface.............................. 75 Table 3-2 Firmware Applications ................................................................ 77 Table 3-3 Default Port Settings .................................................................. 77 Table 3-4 Available Baud Rates ................................................................. 77 Table 3-5 Default GPS NMEA Message Output .......................................... 78 Table 3-6 Correction Age and Elevation Mask Defaults ................................ 78 Table 3-7 Default Differential Mode............................................................. 78 Table 3-8 Beacon Operating Parameters .................................................... 78 Table 3-1 Beacon Receiver Performance - SNR Reading.............................. 86 Table 6-1 NMEA Message Elements ......................................................... 97 Table 6-2 General Commands ................................................................... 99 Table 6-3 GPS Commands ..................................................................... 113 Table 6-4 SBAS Commands ................................................................... 119 Table 6-5 Data Messages ....................................................................... 123 Table 6-6 GGA Data Message Defined..................................................... 124 Table 6-7 GLL Data Message Defined ...................................................... 125 Table 6-8 GSA Data Message Defined ..................................................... 126 Table 6-9 GST Data Message Defined...................................................... 127 Table 6-10 GSV Data Message Defined ................................................... 128 Table 6-11 RMC Data Message Defined ................................................... 129 Table 6-12 RRE Data Message Defined.................................................... 130

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Table 6-13 VTG Data Message Defined.....................................................131 Table 6-14 ZDA Data Message Defined.....................................................132 Table 6-15 RD1 Data Message Defined.....................................................133 Table 6-16 SBX Beacon Commands .........................................................137 Table 6-17 GPS Heading Commands........................................................140 Table 7-1 Binary Message Structure.........................................................159 Table 7-2 Bin 1 Message.........................................................................160 Table 7-3 Bin 2 Message.........................................................................161 Table 7-4 Bin 80 Message .......................................................................162 Table 7-5 Bin 93 Message .......................................................................163 Table 7-6 Bin 94 Message .......................................................................164 Table 7-7 Bin 95 Message .......................................................................165 Table 7-8 Bin 96 Message .......................................................................166 Table 7-9 Bin 97 Message .......................................................................167 Table 7-10 Bin 98 Message .....................................................................168 Table 7-11 Bin 99 Message .....................................................................170 Table 9-1 Troubleshooting........................................................................183 Table A-1 Specifications ..........................................................................185

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Preface Welcome to the Vector PRO Reference Manual and congratulations on purchasing this high-performance GPS compass. This product is based upon the successful heritage of our SLX engine-based GPS products that are renowned for performance and reliability.

The Vector PRO is a complete GPS compass and positioning system in a single enclosure that requires only one power / data cable connection. The Vector PRO has been designed primarily for the Marine market, however it is also suitable for other markets, such as Machine Control and Agricultural Guidance. This reference manual has been written to address the primary use of the Vector PRO in the Marine industry, however the information provided should be sufficiently broad to also satisfy the needs of Vector PRO use in other markets.

The Vector PRO is an integrated system that houses two tightly coupled high-performance GPS receivers, dual GPS antennas, a DGPS beacon module, H-field beacon antenna, power supply, a single-axis gyro, a magnetic compass, and a tilt sensor. The gyro, magnetic compass, and tilt sensor are present to improve system performance and to provide backup heading information in the event that a GPS heading is not available due to signal blockages.

Note - The Vector Lite model is identical to the Vector PRO with the exception that it does contain a DGPS beacon module. If you have purchased the Vector Lite, please ignore the sections of this manual that discuss the beacon signal, receiver operation, and implications to installation relating to the beacon signal.

The GPS antennas inside the Vector PRO are separated by approximately 0.5 m between antenna phase centers, resulting in a 0.5? rms heading performance. The Vector PRO provides industry standard $HEHDT and $HEROT NMEA heading messages at rates of up to 10 Hz and delivers sub-meter positioning (95%) using corrections from

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Space Based Augmentation Systems (SBAS) or its internal SBX beacon demodulator at position update rates of up to 5 Hz.

An additional feature offered by the Vector PRO is our unique COAST™ technology that allows the internal GPS to use old correction data for up to 30 to 40 minutes without dramatically affecting the quality of your positioning. Using COAST, the Vector PRO is less vulnerable to differential signal outages, weak differential signal conditions, differential signal blockage or interference.

The purpose of this manual is to familiarize you with the proper installation, configuration, and operation of your new GPS compass. This document is a comprehensive resource rather than a simple user’s guide in order to place a generous amount of information in one place. We hope this saves you time by providing complete information in a single document and also increases your knowledgebase beyond the basic operation of the Vector PRO. At the same time, we’ve written Chapter 1 such that it condenses much of the heading aspect of the product in one convenient place.

SI-TEX has designed this GPS product to function in a wide array of applications and environments for many years of reliable operation.

Organization This manual contains the following chapters.

Chapter 1: Introduction - provides an introduction to GPS and DGPS technology, and the Vector PRO system.

Chapter 2: Installation - describes how to install the Vector PRO and provides a foundation for interfacing it with an external navigation system or similar device.

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Chapter 3: Overview - provides details on the fundamental operating modes of the Vector PRO system and its associated default parameters.

Chapter 4: Operation - describes how to configure and operate the Vector PRO receiver.

Chapter 5: PocketMAX Utility - describes the general usage of the CSI Wireless PocketMAX utility with the Vector PRO.

Chapter 6: NMEA 0183 - describes the subset of NMEA 0183 commands and queries used to communicate with the Vector PRO.

Chapter 7: Frequently Asked Questions - This chapter provides answers to frequently asked questions about the Vector PRO.

Chapter 8: Troubleshooting - provides you with diagnostic information to aid in determining a source of difficulty for a particular installation.

Appendix A - Specifications: - details the technical characteristics of the Vector PRO system.

Appendix B – Introduction to GPS, SBAS, and Beacon: provides details on GPS, SBAS, and beacon services, and the implications to the Vector PRO

Appendix C - Resources: This appendix lists a number of different resources that may be useful for the advanced user.

The Index provides a listing of the locations of various subjects within this manual.

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Customer Service If you encounter problems during the installation or operation of this product, or cannot find the information you need, please contact your dealer, or CSI Wireless Customer Service. The contact numbers and e-mail address for CSI Wireless Customer Service are:

Telephone number: +1-403-259-3311 Fax number: +1-403-259-8866 E-mail address: [email protected]

Technical Support is available from 8:00 AM to 5:00 PM Mountain Time, Monday to Friday.

To expedite the support process, please have the product model and serial number available when contacting CSI Wireless Customer Service.

In the event that your equipment requires service, we recommend that you contact your dealer directly. However, if this is not possible, you must contact CSI Wireless Customer Service to obtain a Return Merchandise Authorization (RMA) number before returning any product to CSI Wireless. If you are returning a product for repair, you must also provide a fault description before CSI Wireless will issue an RMA number.

When providing the RMA number, CSI Wireless will provide you with shipping instructions to assist you in returning the equipment.

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World Wide Web Site CSI Wireless maintains a World Wide Web home page at the following address.

www.csi-wireless.com

A corporate profile, product information, application news, GPS and DGPS literature, beacon coverage information, and software are available at this site.

Document Conventions Bold is used to emphasize certain points.

Notes, Cautions, and Warnings Notes, Cautions, and Warnings stress important information regarding the installation, configuration, and operation of the Vector PRO system.

Note - Notes outline important information of a general nature.

Cautions - Cautions inform of possible sources of difficulty or situations that may cause damage to the product. Warning - Warnings inform of situations that may cause harm to yourself.

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1. Quick Start The purpose of this chapter is to help you get your Vector PRO running as quickly and painlessly as possible. This chapter is not intended to replace the balance of this reference manual and it assumes that you have a reasonable amount of knowledge with installation and operation of GPS navigation systems.

The Vector PRO is a highly functional system, and as such, it will take care to successfully install and configure. Although this chapter is titled Quick Start, the volume of information presented may be initially overwhelming, however, the default configuration of the Vector PRO provides a functional heading and positioning data output that satisfies many requirements little additional configuration.

Note - The Vector Lite model is identical to the Vector PRO with the exception that it does contain a DGPS beacon module. If you have purchased the Vector Lite, please ignore the sections of this manual that discuss the beacon signal, receiver operation, and implications to installation relating to the beacon signal.

Figure 1-1 shows the Vector PRO mounted on the fixed base.

Figure 0-1 Vector PRO


The Vector PRO is composed of three main pieces; the Vector PRO, the mounts, and the power / data cable. The remaining parts are the manual, screws, and screwdriver bits.

If you are new to GPS and SBAS, we recommend that you consult Appendix B for further information on these services and technology before proceeding.

1.1 Receiving Your Shipment If you find that any of these items are damaged due to shipment, please contact the freight carrier immediately for assistance.

1.2 Unpacking Your Vector PRO System When you unpack your Vector PRO system, please ensure that it is complete by comparing the parts received against the packing slip. Unless your system has intentionally been equipped differently than a standard Vector PRO, you should find the following parts in your system.

• One Vector PRO receiver (P/N 804-0020-01A or greater) or • One Vector Lite (P/N 804-0021-03A or greater) • One pole mount (P/N 603-1002-000) • One fixed mount (P/N603-1001-000) • One power / data cable - 15 m (P/N 051-0063-003) • One Vector PRO Manual (P/N 875-0076-000) • One set of base mounting screws (8 pieces) (P/N 675-1078-000) • Two T-20 Torx screwdriver bit for base mounting (P/N 675-0037-000) • One 1-14-UNS stainless steel jam nut (P/N 676-1003-000) • One stainless steel washer (P/N 678-1039-000)


Note - If, for some reason, you find a discrepancy between your packing slip and the contents of your shipment, please contact the sales person with which you placed your order.

1.3 Vector PRO Interface The Vector PRO features a single power / data connection located on the bottom of the enclosure. This connector, when mated with the cable-mounted connector is weatherproof. Additionally, when the mounting base is fitted, this will provide addition protection from the elements. The following figure shows the Vector PRO’s power / data connection.

Figure 0-2 Cable Interface

1.4 Understanding the Vector PRO The purpose of the Vector PRO system is to provide accurate, reliable heading and position information at high update rates. To accomplish this task, the Vector PRO uses two internal high performance GPS engines and two multipath-resistant antennas for GPS signal processing. One pair of receiver and antenna is designated the primary GPS and the second pair is designated as the secondary GPS.


Positions computed by the Vector PRO are referenced to the phase center of the primary GPS antenna. Heading data references the vector formed from the primary GPS antenna phase center to the secondary GPS antenna phase center.

The following figure shows the location of a heading arrow on the bottom of the Vector PRO enclosure, which defines system orientation. The arrow points in the direction that the heading measurement is computed (when the antenna is installed parallel to the fore-aft line of the vessel). The antenna inside the enclosure directly above the arrow is the secondary antenna.

1.4.1 Moving Base Station RTK The Vector PRO’s internal GPS engines use both the L1 GPS C/A code and carrier phase data to compute the location of the secondary GPS antenna in relation to the primary GPS antenna with a very high sub-centimeter level of precision. The technique of computing the location of the secondary GPS antenna with respect to the primary antenna, when the primary antenna is moving, is often referred to as moving base station Real-Time Kinematic (or moving base station RTK).

RTK technology generally is very sophisticated and requires a significant number of possible solutions to be analyzed where various combinations of integer numbers of L1 wavelengths to each satellite intersect within a certain search volume. The integer number of wavelengths is often referred to as the Ambiguity as they are initially ambiguous at the start of the RTK solution.

The Vector PRO places a constraint on the RTK solution with the prior knowledge of the fact that the secondary GPS antenna has a fixed separation of 0.50 m from the primary GPS antenna on the bracket of the Antenna Array. This reduces the search volume considerably (and hence startup times) since the location of the secondary antenna can theoretically fall only on the surface of a sphere with radius 0.50 m centered on the location of the primary antenna (versus a normal search volume that’s greater than a cubic meter).


1.4.2 Supplemental Sensors - Reduced Search Time In addition to incorporating two internal GPS engines, integrated inside the Vector PRO are a gyro, magnetometer, and a tilt sensor. When used, the combination of the tilt sensor and the magnetometer aid the rate at which a heading solution is computed on startup and also during reacquisition if the GPS heading is lost due to obstructions. Each supplemental sensor may be turned on or off individually, however, the full functionality of the Vector PRO system is realized only when all are used. Each supplemental sensor is inside the Vector PRO enclosure, mounted on the internal printed circuit board.

The tilt sensor reduces the search volume further beyond the volume associated with just a fixed antenna separation, since the Vector PRO knows the approximate inclination of the secondary antenna with respect to the primary. The magnetic sensor is able to provide a general indication of the true heading, reducing the search volume further. The gyro has a similar benefit as the magnetic sensor, however only on reacquisition since it initially requires a GPS heading to self-calibrate. The gyro is more accurate for the short term than the magnetic heading sensor and it further reduces the search volume. Reducing the RTK search volume also has the benefit of improving the reliability and accuracy of selecting the correct heading solution by eliminating other possible, erroneous solutions.

Note - By default, the tilt aiding is turned on, however, the gyro and the magnetic sensors are turned off for shipping. The gyro sensor may be turned on at any time by sending a configuration command to the Vector PRO. The magnetic sensor should be turned on when Vector is mounted in its final location.

1.4.3 Supplemental Sensors - Heading System Backup

The magnetic sensor and the gyro are able to operate as secondary sources of heading during periods of GPS outage due to obstruction. We require that you turn on the magnetic aiding once the installation is complete. You may configure the Vector PRO to use the gyro aiding if


you choose. Since the gyro is more accurate than the magnetic sensor for short periods of outage, if both sensors are used, the Vector PRO will use the gyro for heading initially during an outage. If the outage lasts longer than 60 seconds, the gyro will be deemed to have drifted too far and the Vector PRO will begin outputting a heading based upon the magnetic sensor. There is no user control over the time-out period of the gyro.

If the gyro is turned off and the magnetic sensor is the only secondary heading source, it will provide a heading indefinitely until a GPS heading has been reacquired.

1.5 Installation Overview The following list summarizes the primary installation steps and points for consideration to successfully install and configure the Vector PRO system.

• Choose a mounting location with no structures above its horizon - failure to do so can reduce heading accuracy, startup times, signal reacquisition times, positioning accuracy, and availability of satellite signals from both GPS and SBAS. Make sure the Antenna Array is mounted away from other electronics and antennas (especially active TV antennas) by at least a few feet, preferably more. Keep in mind that the position computed by the Vector PRO is referenced to the phase center of the primary GPS antenna, which is approximately 5.7 cm (2.25”) from the aft-end of the Vector PRO enclosure, residing on its centerline. • You may want to install the Vector PRO on the vessel’s axis so the resulting position from the primary GPS receiver agrees with the centerline of the vessel. The Vector PRO does not support a command to translate its position to the vessel centerline if the enclosure is mounted offset from the centerline. • The location that you choose to mount the Vector PRO should be a quiet location from a radio frequency perspective. This should location should have an omni directional view of the horizon and be mounted reasonably high (keeping in mind serviceability). This will ensure that you minimize outside interference with beacon reception. • Determine how you wish to install the Antenna Array (either along the boat’s fore-aft line or athwartship (perpendicular to it) - this depends on whether or not


you would like to use the second dimension of attitude that the Vector PRO provides - either pitch or roll) • Choose either the fixed or pole mount for the installation, based on what will most easily meet your needs. If you choose to use the pole mount, ensure that once the Vector PRO is mounted, its orientation will not change over time as this will affect the heading result. • Connect the power / data cable to the Vector PRO before you fasten on the fixed mount or pole mount. • Power the Vector PRO only with an input voltage between 8 and 40 VDC. • Install the Vector PRO so that it is horizontal (as best as can be accomplished - this will provide a foundation for performance success when the internal tilt sensor is used to supplement Vector PRO operation). • Compensate for any heading offset of the Vector PRO, its configuration (the default is no compensation) • Configure the NMEA data message output from the Vector (by default, Port A and B output GGA, VTG, GSV, ZDA, HDT, and ROT at 1 Hz) • Configure the baud rates if necessary (default is 19,200 for Port A and B) • Configure the supplementary sensors if necessary (the tilt sensor operates by default and the magnetic sensor and gyro are disabled, but, the magnetic sensor is required to be on after installation is complete) • Configure for your desired mode of differential operation (either SBAS, beacon, or external corrections – SBAS corrections are default) • If you are using the second dimension of attitude provided by the Vector PRO (either roll or pitch, depending on the Antenna Array orientation), configure the Vector PRO appropriately (the default is pitch) • Compensate for pitch / roll error due to installation, within the Vector PRO configuration (the default is no compensation) • If your application does not involve pitching or rolling of more than 10? from horizontal, configuring the Vector PRO for level operation will reduce startup and reacquisition times significantly

1.6 Mounting Configurations and Offset Settings There are two primary mounting orientations possible with the Vector PRO system. The first and most common method is to mount the Vector PRO enclosure pointing in a direction parallel to the axis of the boat, facing the bow. This mounting configuration will provide the ability


for the Vector PRO system to output both heading and the pitch of the vessel.

If a gyrocompass is present onboard, this could be used as truth to calibrate the physical heading of the Vector PRO and its corresponding heading measurements to true heading of the boat by entering a heading bias into the Vector PRO configuration. For example, if a gyrocompass heading provides 183.2? while the Vector PRO provides a heading reading of 184.0?, a bias of -0.8? (the bias is added) should be programmed into the Vector PRO to calibrate its heading. Obviously, the Vector PRO could be adjusted physically to correct for this deviation.

The second method of mounting the Vector PRO system to mount the Vector PRO perpendicular to the boat’s symmetrical axis. This orientation will provide the heading and roll of the vessel. The Vector PRO is then configured with a heading bias of +90? or -90? (depending if the Vector PRO points to port or starboard) to correct the heading.

A feature is present in the Vector PRO to change the sign of the roll / pitch measurement to be positive or negative, depending on the required convention for positive / negative roll, if needed. Consult Chapter 6 for further information.

1.7 Gyro Initialization Process When the gyro is first initializing itself, it is important that the dynamics that the gyro experiences during this warm-up period are similar to the regular operating dynamics. For example, if you will be using the Vector on a high speed, maneuverable craft, it is essential that when gyro aiding in the Vector is first turned on that it be used for the first 5 to 10 minutes in an environment that has high dynamics as well, instead of just sitting stationary.


1.8 NMEA 0183 Message Interface The Vector PRO uses the common NMEA 0183 interface, which allows you to easily make configuration changes by sending text-type commands to the receiver.

Each of the following sections provide the appropriate commands for making the configuration change discussed. The NMEA interface of the Vector PRO is described in more detail in Chapter 6.

1.8.1 Tilt Aiding The Vector PRO’s internal tilt sensor (accelerometer) is enabled by default, is factory calibrated, and constrains the RTK heading solution to reduce startup and reacquisition times.

To turn the tilt-aiding feature off, use the following command.

$JATT,TILTAID,NO<CR><LF>

You may turn this feature back on with the following command.

$JATT,TILTAID,YES,<CR><LF>

To query the Vector PRO for the current status of this feature, issue the following command.

$JATT,TILTAID<CR><LF>

1.8.2 Tilt Sensor Calibration The tilt sensor within the Vector PRO is pre-calibrated during the manufacturing process so it’s not necessary that it be recalibrated in the field. If, for some reason, recalibration is necessary, Chapter 6 describes the command and methodology required to recalibrate this sensor.


1.8.3 Magnetic Aiding For shipping purposes, magnetic aiding is disabled, but, it is required to be turned on and calibrated when the final installation is complete. The Vector’s internal magnetometer reduces the time required to compute a heading solution on startup and during GPS reacquisition by constraining the moving base station RTK solution. Further, it reduces the likelihood of computing the wrong GPS solution. With an approximate heading from the magnetometer, the search volume for the RTK solution is reduced, since the Vector has a general indication of the direction of the secondary GPS antenna.

The magnetic sensor also can provide a secondary source of heading output in the event that a GPS outage occurs due to signal obstruction.

Use of the magnetic aiding feature is now required, but, for shipping purposes, this feature is disabled. In addition to reducing the time required to compute a heading solution, it can also provide a secondary source of heading when a GPS heading is not available. When you are ready to turn the magnetic aiding feature on, there are two different ways of calibrating. The magnetic sensor must be calibrated after the completion of the installation process.

To turn the magnetic-aiding feature on, use the following command.

$JATT,MAGAID,YES<CR><LF>

You may turn this feature back off with the following command.

$JATT,MAGAID,NO<CR><LF>

To query the Vector for the current status of this feature, issue the following command.

$JATT,MAGAID<CR><LF>


1.8.4 Magnetometer Calibration Metallic structures on the vessel affect a compass’ reading, so this effect must be ‘removed’ through the calibration process. Once the Vector is installed in its final location, to use this feature, magnetic aiding must first be turned on, followed by its calibration. A valid GPS heading is mandatory for the calibration process. There are two different ways to calibrate the magnetometer.

The first way is to send a command to clear the current magnetic information to begin the initialization process.

$JATT,MAGCLR<CR><LF>

Then, if you leave the unit powered continuously, it will automatically save the magnetic calibration tables when the system has sufficiently sampled the magnetic field with numerous rotations. Depending on this dynamics of your vessel, this may several days. For instance, if this system is being used on a large cargo vessel that may only see significant rotation during harbor approaches or maneuvers within a port or channel, this process may take many days. Thereafter, there is no further calibration required. If you wish to check if the magnetic information has been saved, you can issue the following command.

$JATT,MAGCAL<CR><LF>

The second method requires more work up front, but ensures your magnetic calibration information is up to date and complete within a short period of time. A command to clear the current magnetic information must first be sent to begin the initialization process, followed by slowly rotating the vessel a full 360? approximately 3 to 10 times. Calibration should be performed in a clear environment without any potential satellite blockages to minimize any possible errors during the process. The command to initialize the magnetic calibration process follows.



Once the command has been issued, the vessel needs to rotate 360? three to four times. The following command can be sent during the calibration procedure to ‘ask’ the Vector if the calibration is complete and if so, to automatically save it to memory for subsequent power cycles.


If the Vector enclosure is reinstalled in a different location, even on the same vessel, you will need to clear the calibration table with the $JATT,MAGCLR command and complete the new calibration. Similarly, if any objects containing metal are moved near or away from the sensor, this command will need to be sent to the receiver and a new calibration performed.

Note - It is very important to perform the calibration only after the installation of the Vector has been confirmed to be complete. If the Vector’s location is changed, you will need to clear the calibration and recalibrate. A valid GPS heading is required during the calibration process.

1.8.5 Gyro Aiding The Vector PRO’s internal gyro is not used by default, however it can offer two benefits. It will shorten reacquisition times when a GPS heading is lost, due to obstruction of satellite signals, by reducing the search volume required for solution of the RTK. It will also provide an accurate substitute heading for a short period (depending on the roll and pitch of the vessel) ideally seeing the system through to reacquisition.

Should you wish to use gyro-aiding, you will need to turn it on using the following command.

$JATT,GYROAID,YES<CR><LF>

If you wish to turn this feature off, the use the following command.

$JATT,GYROAID,NO<CR><LF>


If you wish to request the status of this message, send the following command.

$JATT,GYROAID<CR><LF>

1.8.6 Time Constants The Vector PRO incorporates user-configurable time constants that can provide a degree of smoothing to the heading, course over ground, and speed measurements. The following sections describe how to configure their values.

1.8.6.1 Heading Time Constant The heading time constant allows you to adjust the level of responsiveness of the true heading measurement provided in the $HEHDT message. The default value of this constant is 2.0 seconds of smoothing when the gyro is enabled. The gyro by default is enabled, but can be turned off. By turning the gyro off, the equivalent default value of the heading time constant would be 0.5 seconds of smoothing. This is not done automatically, and therefore must be entered manually by the user. Increasing the time constant will increase the level of heading smoothing.

The following command is used to adjust the heading time constant.

$JATT,HTAU,htau<CR><LF>

Where ‘htau’ is the new time constant that falls within the range of 0.0 to 3600.0 seconds.

Depending on the expected dynamics of the vessel, you may wish to adjust this parameter. For instance, if the vessel is very large and is not able to turn quickly, increasing this time is reasonable. The resulting heading would have reduced ‘noise’, resulting in consistent values with time. However, artificially increasing this value such that it does not agree with a more dynamic vessel could create a lag in the heading measurement with higher rates of turn. A convenient formula for determining what the level of smoothing follows for when the gyro is in


use. If you are unsure on how to set this value, it’s best to be conservative and leave it at the default setting.

htau (in seconds) = 40 / maximum rate of turn (in ?/s) – gyro ON

htau (in seconds) = 10 / maximum rate of turn (in ?/s) – gyro OFF

You may query the Vector for the current heading time constant by issuing the same command without an argument.

$JATT,HTAU<CR><LF>

Note - If you are unsure of the best value for this setting, it’s best to be conservative and leave it at the default setting of 2.0 seconds when the gyro is on and at 0.5 seconds when the gyro is off.

1.8.6.2 Pitch Time Constant The pitch time constant allows you to adjust the level of responsiveness of the pitch measurement provided in the $PSAT,HPR message. The default value of this constant is 0.5 seconds of smoothing. Increasing the time constant will increase the level of pitch smoothing.

The following command is used to adjust the pitch time constant.

$JATT,PTAU,ptau<CR><LF>

Where ‘ptau’ is the new time constant that falls within the range of 0.0 to 3600.0 seconds.

Depending on the expected dynamics of the vessel, you may wish to adjust this parameter. For instance, if the vessel is very large and is not able to pitch quickly, increasing this time is reasonable. The resulting pitch would have reduced ‘noise’, resulting in consistent values with time. However, artificially increasing this value such that it does not agree with a more dynamic vessel could create a lag in the pitch measurement. A convenient formula for determining what the level of


smoothing follows. If you are unsure on how to set this value, it’s best to be conservative and leave it at the default setting.

ptau (in seconds) = 10 / maximum rate of pitch (in ?/s)

You may query the Vector PRO for the current pitch time constant by issuing the same command without an argument.

$JATT,PTAU<CR><LF>

Note - If you are unsure of the best value for this setting, it’s best to be conservative and leave it at the default setting of 0.5 seconds.

1.8.6.3 Heading Rate Time Constant The heading rate time constant allows you to adjust the level of responsiveness of the rate of heading change measurement provided in the $HEROT message. The default value of this constant is 2.0 seconds of smoothing. Increasing the time constant will increase the level of heading smoothing.


$JATT,HRTAU,hrtau<CR><LF>

Where ‘hrtau’ is the new time constant that falls within the range of 0.0 to 3600.0 seconds.

Depending on the expected dynamics of the vessel, you may wish to adjust this parameter. For instance, if the vessel is very large and is not able to turn quickly, increasing this time is reasonable. The resulting heading would have reduced ‘noise’, resulting in consistent values with time. However, artificially increasing this value such that it does not agree with a more dynamic vessel could create a lag in the rate of heading change measurement with higher rates of turn. A convenient formula for determining what the level of smoothing follows. If you are


unsure on how to set this value, it’s best to be conservative and leave it at the default setting.

hrtau (in seconds) = 10 / maximum rate of the rate of turn (in ?/s2)

You may query the Vector PRO for the current heading rate time constant by issuing the same command without an argument.

$JATT,HRTAU<CR><LF>


1.8.6.4 Course over Ground Time Constant The course over ground (COG) time constant allows you to adjust the level of responsiveness of the COG measurement provided in the $GPVTG message. The default value of this constant is 0.0 seconds of smoothing. Increasing the time constant will increase the level of COG smoothing.

The following command is used to adjust the COG time constant.

$JATT,COGTAU,cogtau<CR><LF>

Where ‘cogtau’ is the new time constant that falls within the range of 0.0 to 3600.0 seconds.

COG is computed using the primary GPS engine only, and its accuracy is dependant upon the speed of the vessel (noise is proportional to 1/speed) and when stationary, this value is invalid.

As with the heading time constant, the setting of this value depends upon the expected dynamics of the vessel. If a boat is highly dynamic, this value should be set to a lower value since the filtering window needs be shorter in time, resulting in a more responsive measurement. However, if a vessel is very large and has much more resistance to change in its motion, this value can be increased to reduce


measurement noise. The following formula provides some guidance on how to set this value. If you are unsure what is the best value for this setting, it’s best to be conservative and leave it at the default setting.

cogtau (in seconds) = 10 / maximum rate of change of course (in ?/s)

You may query the Vector PRO for the current heading time constant by issuing the same command without an argument.

$JATT,COGTAU<CR><LF>


1.8.6.5 Speed Time Constant The speed time constant allows you to adjust the level of responsiveness of the speed measurement provided in the $GPVTG message. The default value of this parameter is 0.0 seconds of smoothing. Increasing the time constant will increase the level of speed measurement smoothing.

The following command is used to adjust the speed time constant.

$JATT,SPDTAU,spdtau<CR><LF>

Where ‘spdtau’ is the new time constant that falls within the range of 0.0 to 3600.0 seconds.

Speed is computed using the primary GPS engine only. As with the heading time constant, the setting of this value depends upon the expected dynamics of the vessel. If a boat is highly dynamic, this value should be set to a lower value since the filtering window would be shorter, resulting in a more responsive measurement. However, if a vessel is very large and has much more resistance to change in its motion, this value can be increased to reduce measurement noise. The following formula provides some guidance on how to set this value initially, however, we recommend that you test how the revised value


works in practice. If you are unsure what is the best value for this setting, it’s best to be conservative and leave it at the default setting.

spdtau (in seconds) = 10 / maximum acceleration (in m/s2)


$JATT,SPDTAU<CR><LF>


1.8.7 Level Operation If the Vector PRO system will operate in a level plane (within ?10? from horizontal), an additional constraint can be placed upon the RTK heading solution in order to reduce the RTK search time and increase solution robustness. This feature, referred to as ‘level operation’ is disabled by default but can be invoked using the following command.

$JATT,LEVEL,YES<CR><LF>

To turn this feature off, issue the following command.

$JATT,LEVEL,NO<CR><LF>

To determine the current status of this message, issue the following command.

$JATT,LEVEL<CR><LF>

1.8.8 Heading Compensation You may adjust the heading output from the Vector PRO in order to correct for any physical offset of the enclosure from the true heading of the vessel.


$JATT,HBIAS,x<CR><LF>

Where x is a bias that will be added to the Vector PRO’s heading, in degrees. The acceptable range for the heading bias is -180.0? to 180.0?. The default value of this feature is 0.0?.

To determine what the current heading compensation angle is, send the following message to the Vector PRO.

$JATT,HBIAS<CR><LF>

1.8.9 Configuring for Pitch or Roll The mounting orientation of the Vector PRO determines if the second dimension of vessel orientation will be roll or pitch. As mentioned, if you install the Vector PRO parallel to the axis of the boat, it will provide pitch in addition to heading. If the Array were mounted athwartship (perpendicular to the vessel axis), the second dimension of orientation would be roll.

If you install the Vector PRO in a parallel direction as the boat’s axis, you do not need to make any configuration changes to receive the pitch measurement - you need to only turn the appropriate message on (the $PSAT,HPR message).

If you wish to get the roll measurement, you will need to install the Vector PRO perpendicular to the vessel’s axis, and send the following command to the unit.

$JATT,ROLL,YES<CR><LF>

If you wish to return the Vector PRO to its default mode of outputting the pitch measurement, issue the following command.

$JATT,ROLL,NO<CR><LF>

You may query the Vector PRO for the current roll / pitch status with the following command.


$JATT,ROLL<CR><LF>

1.8.10 Configuring Negative Pitch or Roll When the secondary GPS antenna is below the primary GPS antenna, the angle from the horizon at the primary GPS antenna to the secondary GPS antenna is considered negative by default.

Depending on your convention for positive and negative pitch / roll, you may wish to change the sign (either positive or negative) of the pitch / roll. To do this, issue the following command.

$JATT,NEGTILT,YES<CR><LF>

This will cause the pitch measure to be positive when the secondary GPS antenna is below the primary GPS antenna.

To return the sign of the pitch / roll measurement to its original value, issue the following command.

$JATT,NEGTILT,NO<CR><LF>

To query the Vector PRO for the current state of this feature, issue the following command.

$JATT,NEGTILT<CR><LF>

1.8.11 Pitch / Roll Compensation If you have installed the Vector PRO and you have it correctly aligned, but there is a bias in the amount of tilt that it has, or it’s not fully horizontal, you may adjust the pitch / roll output from the Vector PRO in order to calibrate the measurement. The following NMEA message allows to you to calibrate the pitch / roll reading from the Vector PRO.

$JATT,PBIAS,x<CR><LF>


Where x is a bias that will be added to the Vector PRO’s pitch / roll measure, in degrees. The acceptable range for the heading bias is -15.0? to 15.0?. The default value of this feature is 0.0?.

To determine what the current pitch compensation angle is, send the following message to the Vector PRO.

$JATT,PBIAS<CR><LF>

Note - The pitch / roll bias is added after the negation of the pitch / roll measurement (if so invoked with the $JATT,NEGTILT command).

1.8.12 Forcing a New RTK Search You may force the Vector PRO to reject the current RTK heading solution, and have it begin a new search with the following command.

$JATT,SEARCH<CR><LF>

1.8.13 Summary Command This command is used to receive a summary of the current Vector PRO settings. This command has the following format.

$JATT,SUMMARY<CR><LF>

The Vector PRO will reply with the following output.

$>JATT,SUMMARY,TAU:H=0.50,HR=2.00,COG=0.00,SPD=0.00,BIAS:H=0.00,P=0.00,FLAG_HEX:GN-RMTL=01

Chapter 6 summarizes this output in detail.

1.8.14 HELP command The Vector PRO supports a command that you can use to get a short list of the supported commands if you find yourself in the field without documentation.


This commands has the following format.

$JATT,HELP<CR><LF>

The response to this command will be the following.

$>JATT,HELP,CSEP,MSEP,EXACT,LEVEL,HTAU,HRTAU,HBIASPBIAS,NEGTILT,ROLL,TILTAID,TILTCAL,MAGAID,MAGCAL,MAGCLR,

GYROAID,COGTAU,SPDTAU,SEARCH,SUMMARY

1.8.15 $HEHDT Message This message provides true heading of the vessel. This is the direction that the vessel (Vector PRO) is pointing and is not necessarily the direction of vessel motion (the course over ground), although they may be the same.

The COG measurement in the $GPVTG message describes the true direction of travel of the boat as a result of the vessel trust, currents, wind, etc. Please note that the COG measure is derived from the primary GPS receiver only and is less accurate than the true heading derived using the RTK solution that uses both GPS receivers.

The $HEHDT message output rate may be configured with the following command.

$JASC,HEHDT,rate<CR><LF>

Where ‘rate’ may be any of the following values expressed in Hz: 0, 1, 5, 10, or 0.2.

The output from the $JSHOW<CR><LF> command provides the current output rate setting for this message.

The details of this command and the $HEHDT are described in Chapter 6.


1.8.16 $HEROT Message This message provides rate of turn of the vessel and has units of degrees per second.

The $HEHDT message output rate may be configured with the following command.

$JASC,HEROT,rate<CR><LF>


The output from the $JSHOW<CR><LF> command provides the current output rate setting for this message.

The details of this command and the $HEROT message are described in Chapter 6.

1.8.17 Proprietary $PSAT,INTLT Message The $PSAT,INTLT data message is a proprietary NMEA sentence that provides the tilt measurement from the internal inclinometer, in degrees. This message can be output only at 1 Hz and is turned on using the following command.

$JASC,INTLT,1<CR><LF>

To turn this message off, use the following command.

$JASC,INTLT,0<CR><LF>

The details of this command and the $PSAT,INTLT message are described in Chapter 6.

1.8.18 Proprietary $PSAT,HPR Message The $PSAT,HPR message is a proprietary NMEA sentence that provides the heading, pitch / roll information, and time in a single data


message. The output of this data message is controlled using the following message.

$JASC,HPR,rate<CR><LF>


The details of this command and the $PSAT,HPR data message are described in Chapter 6.


2. Installation This chapter contains instructions and recommendations for the installation of the Vector PRO GPS heading system.

2.1 System Parts List The following list of standard equipment is included with the Vector PRO.

• One Vector PRO receiver (P/N 804-0020-01A or greater) or One Vector Lite (P/N 804-0021-03A or greater)

• One pole mount (P/N 603-1002-000) • One fixed mount (P/N603-1001-000) • One power / data cable - 15 m (P/N 051-0063-003) • One Vector PRO Manual (P/N 875-0076-000) • One set of base mounting screws (8 pieces) (P/N 675-1078-000) • Two T-20 Torx screwdriver bit for base mounting (P/N 675-0037-000) • One 1-14-UNS stainless steel jam nut (P/N 676-1003-000) • One stainless steel washer (P/N 678-1039-000)

2.2 Installation Overview The following sub-sections summarize the installation steps for the Vector PRO, which differs depending on which mount that you choose.

2.2.1 Fixed Base Installation When using the fixed base mount, the following list provides an overview of the installation process.

• Choose a mounting location for the Vector PRO • Determine if you wish to use the second dimension of attitude being either the roll or the pitch. If you wish to use the roll measure, you must install the Vector PRO perpendicular to the direction of travel and then accommodate for this orientation in the receiver software configuration)


• Connect the power / data cable connector to the Vector PRO connector, ensuring the locking ring has positively locked • Fasten the Vector PRO enclosure to the fixed base mount • Route the cable from this location through fixed base mount, through the mounting surface, and any bulkheads as necessary (leave enough slack to remove the Vector PRO from the fixed base as necessary) • Install the fixed base mount without tightening down the screws fully, to allow for adjustment at a later step • Adjust the orientation of the Vector PRO as necessary and secure it when complete (you may wish to use the ‘alignment sights’ on the top of the enclosure for this purpose) • Interface the Vector PRO to a PC computer for configuration of the communication settings, data message output, and any offset that’s necessary.

2.2.2 Pole-mounting Base Installation The following list details the installation process when using the pole mount.

• Choose a mounting location for the Vector PRO • Determine if you wish to use the second dimension of attitude being either the roll or the pitch. If you wish to use the roll measure, you must install the Vector PRO perpendicular to the direction of travel and then accommodate for this orientation in the receiver software configuration) • Install the mounting pole as necessary • Thread the hex nut and then the washer onto the threaded pole • Thread the Vector PRO’s pole-mounting base onto the threaded pole (do not tighten down at this point to allow for adjustment of orientation at a later time) • Route the cable through the pole mount, pole, and any bulkheads as necessary (leave enough slack to remove the Vector PRO from the pole-mounting base as necessary) • Connect the cable-mounted connector to the Vector PRO bulkhead connector, ensuring the locking ring has positively locked • With the Vector PRO approximately facing the final direction, align the pole-mounting base and nut / washer combination to the GPS compass. Fasten the Vector PRO enclosure to the pole-mounting base • Adjust the orientation of the Vector PRO as necessary and secure it when complete (you may wish to use the ‘alignment sights’ on the top of the enclosure for this purpose) • Interface the Vector PRO to a PC computer for configuration of the communication settings, data message output, and any offset that’s necessary.


2.3 Vector PRO Interface The following figure shows the location of the connector located on the bottom of the Vector PRO enclosure. This connector is the only interface to the product and includes the power input and the serial communication input / output.

Figure 2-1 Vector PRO Interface

2.4 Choosing a Mounting Location When considering the various mounting locations present, you will need to give regard for both GPS (and hence SBAS) and beacon reception. The following two sections provide information that will help you determine the best location for the Vector PRO.

2.4.1 GPS Reception When considering various locations to mount the Vector PRO, consider the following recommendations closely.

• The primary GPS engine inside the Vector PRO computes a position based upon measurements from each satellite to the internal primary GPS antenna


element. Mount the Vector PRO in the location for which you desire a position with respect to the primary GPS antenna. • When choosing a location to mount the antenna, please ensure that there is an unobstructed hemisphere of sky available to the Vector PRO. This will ensure that GPS and SBAS satellites are not masked by obstructions, potentially reducing system performance. • It’s important to locate any transmitting antennas away from the Vector PRO by at least a few feet. This will ensure that tracking performance is not compromised, giving you the best performance possible. • Make sure that you have enough cable length to route into the vessel, in order to reach a breakout box or terminal strip. • Do not locate the antenna where environmental conditions exceed those specified in Section 2.4.

2.4.2 Beacon Reception When using the Vector PRO’s internal beacon receiver as the correction source, you will need to consider the possible mounting locations from a perspective of ambient noise within the beacon band. The following list provides some general guidelines for deciding upon a location with respect to maximizing beacon performance.

• Ensure that the antenna is as far as possible from all other equipment that emits Electromagnetic Interference (EMI), including DC motors, alternators, solenoids, radios, power cables, display units, and other electronic devices • If you are installing the antenna on a vessel (using DGPS beacon corrections), mount the Vector PRO antenna as high as possible, considering maintenance and accessibility. In addition, ensure that the antenna is lower than the highest metal object on the vessel. • If a radar system is present, mount the antenna outside the path of the radar beam

The Vector PRO’s internal beacon receiver calculates a Signal to Noise Ratio (SNR), measured in dB (Decibels) that indicates the receiver’s performance. The SNR is height of the signal above the noise floor. The higher the SNR, the better your beacon receiver is demodulating the signal. The optimum antenna location will be a position where your average SNR is highest. You should turn on all accessories that you intend to use during normal operation when locating the best position for the antenna. By monitoring the SNR, you can determine the optimum


location with respect to beacon reception. The SNR is available in the $CRMSS NMEA message described in Chapter 6.

Note – Beacon data is only accessible via primary GPS Port A and B. The secondary GPS Port A does not provide access to the beacon receiver.

2.5 Environmental Considerations The Vector PRO is designed to withstand the harsh outdoor environment, however, there are specific environmental limits that you should ensure are met when storing and using this system.

The Vector PRO is designed to be stored between -40?C and +85?C. The operating temperature range is -30?C and +70?C. It is designed for harsh marine use and will operate in an environment with 100% relative humidity.

2.6 Power Considerations The Vector PRO is powered with an input voltage of between 8 and 40 VDC. For best performance, the supplied power should be continuous and clean. Table 2-1 details the power specifications of the Vector PRO.

Table 2-1 Power Requirements

Input Voltage Input Current Input Power

8 to 40VDC <360 mA @ 12 VDC <4.5 W maximum

The Vector PRO power supply features reverse polarity protection but will not operate with reverse polarity power.

2.7 Electrical Isolation


The Vector PRO features a power supply that is isolated from the communication lines. Further, the PC-ABS plastic enclosure isolates the electronics mechanically from the vessel. This addresses the issue of vessel hull electrolysis.

2.8 Vector PRO Mounting The Vector PRO may be mounted with either the fixed base or pole-mounting base, both supplied with the system.

The fixed base allows you to mount the Vector PRO on a wide array of flat surfaces, such as radar platforms. The pole mount is designed for use with 1-14-UNS-2B threaded mounts, such as pole and rail mounts.

Note - Installations that use the pole mount require the use of the supplied hexagonal jam nut and flat washer in order to mechanically couple the Vector PRO system to the pole mount with less stress on the threads. If the nut / washer combination is not used, failure of the pole mounting base could occur, which may damage the Vector PRO. Any such damage to the Vector PRO system resulting from not using the nut / washer combination is not covered under warranty.


The following figure shows the Vector PRO mounted with the fixed base.

Figure 2-2 Vector PRO with Fixed Mount Base

The following figure shows the Vector PRO with the pole mount.

Figure 2-3 Vector PRO with Pole Mount Base


2.8.1 Fixed Base Mounting The fixed base supplied with the Vector PRO is intended to allow you to mount the system to a flat surface. This surface may be something that you fabricate for the sake of the installation, or may be something that already exists on your vessel or an off-the-shelf item, such as a radar mounting plate.

2.8.1.1 Fixed Base Overview As you can see from Figure 2-4, the fixed base has the following features:

• Six holes for mounting onto the Vector PRO enclosure • A channel through the mount for the power / data cable. • Two small keys that aid the alignment of the base to the enclosure. • Four slots used for fastening the mounted enclosure to the vessel. • Four tunnels that allow you to route the cable outside the base and along the mounting surface.

The slots on the bottom of the base allow for a degree of adjustment when the Vector PRO is secured in its final location.

Note - You do not necessarily need to orient the antenna precisely as you can enter a software offset to accommodate for any bias in heading measurement due to installation.

The base also features four tunnels that allow you to bring the power / data cable out from within the mount in order to route it along the surface of the plate beneath the Vector PRO system. Alternatively, you may wish to route the power / data cable through the mounting surface rather than bringing it out through one of the tunnels.


Figure 2-4 Fixed Mount Base

Figure 2-1 Bottom View of Fixed Mount Base


2.8.1.2 Before you start To mount the antenna on the fixed base

• Decide if you need the roll measurement, as if you do, the Antenna Array will need to be installed orthogonal to the vessel axis. If you don’t require roll, install the Vector PRO parallel with the vessel’s axis. • Choose a location that meets the requirements of Section 2.5 • Using the fixed base as a template, mark and drill the mounting holes as necessary for the mounting surface • Alternatively, you may rail mount the Antenna Array with appropriate hardware

2.8.1.3 Routing the cable To install the Vector PRO using the fixed base, insert either end of the power / data cable through the center of the fixed base as shown in the following two figures.

Figure 2-6 Running Cable Through Fixed Base Mount


Figure 2-7 Running Cable Through Fixed Base

Align the connector keyway of the cable to the key of the connector mounted on the Vector PRO enclosure as show in Figure. Insert the cable-mount connector into the bulkhead connector, aligning the locking ring at the same time.

Figure 2-8 Power / Data Cable Key and Keyway


Once inserted, rotate the ring clockwise until it locks. The locking action is firm, but you will feel a positive ‘click’ when it has locked, as shown in the following figure.

Figure 2-9 Connecting the Power / Data Cable to the Vector PRO

Once you have secured the connector, slide the fixed base up to the bottom of the Vector PRO enclosure. There are two alignment keys on top of the base that must fit into two holes of the Vector PRO enclosure. Once you have aligned the base, use a screwdriver fitted with the supplied Torx T20 bit to fasten the base to the enclosure using the supplied screws. These screws self tap a thread in the blind screw holes of the enclosure. Fasten the screws firmly, but be careful not to strip the thread.

Note - The base is not intended to be removed and re-fastened frequently. Frequent removal of the base from the enclosure may result in failure of the screw hole threads. Stripped threads are not covered under the product warranty.

The following two figures show the location of the screw holes.


Figure 2-10 Fastening the Fixed Base to the Vector PRO

Figure 2-11 Fastening the Fixed Base to the Vector PRO

Once you have fastened the fixed base to the Vector PRO enclosure using six mounting screws, you are ready to fasten the assembly to your mounting surface. We recommend that you use machine screws that have an Allen Key head (hexagonal) and an “L-shaped” Allen Key,


as there may not be sufficient clearance between the bottom of the antenna and your mounting surface to use a normal screwdriver.

Note - As we do not supply the mounting surface, you will need to supply the appropriate fastening hardware required to complete the installation of the Vector PRO and mount assembly.

2.8.2 Pole and Rail Mounting You may choose to pole-mount or rail-mount the Vector PRO as opposed to the magnetic mounting approach. The pole mount incorporates a 1-14-UNS thread. To aid in the installation of the Vector PRO, we have supplied a hex jam nut and washer. These are used to secure the antenna in a particular direction without bottoming out the system on the threaded pole. Additionally, the nut and washer distributes forces associated with vibration onto the bottom surface of the Vector PRO pole mount.

Caution – Do not bottom out the Vector PRO pole base on the threaded mount. Such manner can damage the system. Use of the jam nut and washer are mandatory for pole mounting. Any damage resulting from not using these pieces to mount the Vector PRO will not be covered under warranty.

2.8.2.1 Before you start To mount the antenna on the pole mount bracket:

• Decide if you need the roll measurement, as if you do, the Antenna Array will need to be installed orthogonal to the vessel axis. If you don’t require roll, install the Vector PRO parallel with the vessel’s axis. • Choose a location that meets the requirements of Section 2.5 • Mark and drill the mounting holes as necessary for the threaded pole as necessary • Alternatively, you may rail mount the Antenna Array with appropriate hardware

2.8.2.2 Pole Mount Installation and Preparation You will need to supply the pole or rail mount hardware that you wish to use. Once you have installed the pole or rail mount, thread the


hexagonal jam nut onto to the mount, followed by the stainless steel washer, both supplied with the Vector PRO system. You should thread the nut onto the mount approximately 8 to 10 full turns to provide adequate mounting thread for the pole mount base. The following figure illustrates this step.

Figure 2-12 Threading on the Lock Nut and Washer

2.8.2.3 Routing the Cable When mounting the Vector PRO using the pole mount, the cable must be run first through the center of the pole mount base (from top to bottom), through the pole, and then through any bulkheads as needed (the power / data connector is too large to fit through the threaded portion of the pole mount base).

Note - Be sure to have some slack to move the cable in and out of the pole mount by a few inches. This will allow you to connect the cable to the Vector PRO easily.

The following three figures detail the process of routing the cable.


Figure 2-13 Running the Cable Through the Pole Base

Figure 2-14 Running the Cable Through the Pole Base


Figure 2-14 Running the Cable Through the Pole Mount

Once you have routed the cable correctly through the pole mount base and the mounting pole, the mounting assembly should look like the following figures.

Figure 2-15 Completed Cable Run

2.8.2.4 Mounting the Pole Mount Base Thread the pole mount base onto the pole mount four to five full turns.


Figure 2-1 Threading the Pole Base onto the Mount

Ensure that there’s a gap between the lock nut and washer, and the pole mount base as shown in the following figure. This will allow you to orient the combination of Vector PRO and pole mount base to the vessel.

Figure 2-17 Pole Base Threaded onto Mount

2.8.2.5 Connecting the Cable to the Vector PRO At this point, fasten the cable to the Vector PRO connector. Notice that the connector on the receiver enclosure has a key and that the cable-


mount connector has a keyway. The key and keyway need to align as you insert the cable-mount connector into the bulkhead connector.

Note – you may have to align the locking ring on the cable-mount connector as you insert it into the bulkhead connector, to ensure that it seats properly.

Once the cable-mount connector has seated fully, rotate the locking ring clockwise until it locks. You will feel the ring ‘click’ when it has locked.

The following two figures show the key, keyway, and the connection when complete.

Figure 2-18 Power / Data Cable Key and Keyway


Figure 2-19 Connected Power / Data Cable

2.8.2.6 Fastening the Vector PRO to the Pole Mount Base The next step is to fasten the Vector PRO enclosure to the pole mount base using the supplied self-tapping screws. The following figure illustrates this process. There are two alignment keys on top of the base that must fit into two holes of the Vector PRO enclosure. Once you have aligned the base, use a screwdriver fitted with the supplied Torx T20 bit to fasten the base to the enclosure using the supplied screws. These screws self tap a thread in the blind screw holes of the enclosure. Fasten the screws firmly, but be careful not to strip the thread.

Note - The base is not intended to be removed and re-fastened frequently. Frequent removal of the base from the enclosure may result in failure of the screw hole threads. Stripped threads are not covered under the product warranty.


Figure 2-20 Fastening the Pole Base to the Vector PRO

The next step is to rotate the hex nut and washer up to the bottom surface of the pole mount base. Do not tighten them at this point as you will need to align the Vector PRO.

Figure 2-21 Threading the Lock Nut Against the Pole Base

Orient the Vector PRO using the sights on the top of the enclosure. Using an adjustable wrench, tighten the lock nut against the Vector


PRO while ensuring accurate alignment of the antenna system. Section 2.8.3 details the use of the alignment sights.

2.8.2.7 Alignment of the Vector PRO

Figure 2-22 Locking the Vector PRO once Aligned

Note - You will need to tighten the locking nut against the pole mount base tightly. To ensure that you don’t over tighten the nut, periodically check to see how secure the antenna system is, as mounted on the pole. If it’s loose, tighten the lock nut further until you can not move it.

2.8.3 Vector PRO Alignment The top of the Vector PRO enclosure incorporates a pair of sight design features for assisting antenna alignment. The sights will help you to align the enclosure with respect to an important feature on your vessel.

To use the sights, center the small post on the opposite side of the enclosure from you, within the channel made in the medallion located in the center of the enclosure top as shown in the two following figures. Alignment accuracy when looking through the long site is approximately


? 1?. Using the short site, alignment is approximately accurate to ? 2.5?.

Figure 2-23 Lining up the Alignment Sight

Figure 2-24 Correctly Lined-up Alignment Sight

If you have another accurate source of heading data on your vessel, such as a gyrocompass, you may use its data to correct for a bias in Vector PRO alignment within the Vector PRO software configuration.


Alternatively, you may wish to physically adjust the heading of the Vector PRO so that it renders the correct heading measurement, however, adding a software offset is an easier process.

2.9 Routing and Securing the Power / Data Cable The Vector PRO comes with a 15 m power / data cable. When choosing a route for the antenna extension cable:

• Avoid running the cable in areas of excessive heat • Keep the cable away from corrosive chemicals • Do not run the cable through door or window jams • Keep the cable away from rotating machinery • Do not bend excessively or crimp the cable • Avoid placing tension on the cable • Secure along the cable route using plastic tie wraps as necessary

Warning - Improperly installed cables near machinery can be dangerous.

2.10 Interfacing the Vector PRO The Vector PRO uses a single cable for application of power and to facilitate the input and output operations. The power cable is 15 m in length and is terminated on the receiver end with an environmentally sealed 18-pin connection. The opposite end is un-terminated and requires field stripping and tinning.

Depending on your application and installation needs, you may have to shorten this cable. If so, this is a simple matter.

However, if you require a longer cable run than 15 m, we recommend that you bring the cable into a break-out box that incorporates terminal strips, within the vessel. To lengthen the serial lines inside the vessel, ensure that you use 20 gauge twisted pairs and minimize the additional


wire length. The RS-422 signal should be used for longer cable runs as compared to the RS-232 ports, as it’s more resistant to noise and attenuation.

When lengthening the power input leads to the Vector PRO, please ensure that the additional voltage drop is small enough that your power system can continue to power the system above the minimum voltage of the system. Wire of 18 gauge or larger should also be used.

2.10.1 Power / Data Cable Pin-Out The following table details the wire colors and their associated functions. Each wire color is twisted with a black wire.

Table 2-1 Wire Color Interface

Wire Pairs Signal

Red Power input (8 to 40 VDC) Black Power ground Blue Primary GPS Port A transmit RS-232

Black with White stripe Primary GPS Port A receive RS-232 White Primary GPS Port B transmit RS-232

White with Black stripe Signal Ground Green Primary GPS Port A transmit RS-422+

Green with White stripe Primary GPS Port A transmit RS-422- Brown Secondary GPS Port A transmit RS-232

Brown with White stripe Secondary GPS Port A receive RS-232 Yellow Primary GPS Port B transmit RS-422+

Yellow with Black stripe Primary GPS Port B transmit RS-422- Orange 1 pulse per second + (1 PPS +)

Orange with White stripe 1 pulse per second - (1 PPS -) Bare Wire Drain for RF shielding – Do not

connect


Note - To identify the function of each black wire, you need to examine which color it is twisted with. For instance, if you look at one black wire and it’s twisted with a green wire, the function of that black wire is ‘Primary GPS Port A transmit RS-422’.

2.10.2 Connecting to a power source The first step to powering the Vector PRO is to terminate the wires of the power cable as required. There are a variety of power connectors and terminals on the market from which to choose, depending on your specific requirements

Caution - do not apply a voltage higher than 40 VDC as this will damage the receiver and void the warranty

To interface the Vector PRO power cable to the power source:

• Connect the red wire of the cable’s power input to DC positive (+) • Connect the black wire of the cable’s power input to DC negative (-)

The Vector PRO smart antenna features reverse polarity protection to prevent damage if the power leads are accidentally reversed. The Vector PRO, however, does not function with reverse polarity.

Once the Vector PRO system has been installed, you’re ready to turn the system on by applying power to it. The Vector PRO smart antenna will start when an acceptable voltage is applied to the power leads of the extension cable. Be careful not to provide a voltage higher than the input range as this will damage the antenna.

2.10.3 Overview of Serial Port Interface The Vector PRO offers position and heading data via both RS-232 and RS-422 level serial ports. The answer of which serial port level to use resides with the serial port level(s) supported by the other electronics involved. You may find that the other electronics need either serial port level or mixture of both.

The following sections describe the two serial port levels supported by the Vector PRO.


2.10.3.1 RS-232 Interface Level The Vector PRO features two full duplex (bi-directional) RS-232 serial ports, one each for the primary and secondary GPS receivers. In addition to outputting data, these ports are used for firmware upgrades.

Warning - the port for the secondary receiver may be used for output of heading data only, and specifically, the $HEHDT and $PSAT,HPR data messages. All other messages should not be considered accurate. This port has been included primarily for firmware upgrades to the secondary GPS receiver.

The primary GPS receiver full duplex serial port is Port A, however the primary receiver also features a second half-duplex RS-232 serial port output, Port B (an additional, programmable output data port). You may configure Port B through Port A, so the input to Port B is not required.

In addition to supporting RS-232 signal levels, data output from both Port A and B are available with an RS-422 interface level. Again, these signals are outputs only as you configure the data output from Port A and B through the RS-232 Port A input line.

Note - For general configuration of the Vector PRO, such as adjusting the time constants, primary GPS Port A should be used.

2.10.3.2 RS-422 Interface Level The RS-232 interface level is intended to be used with one-to-one communications, where the serial port communicates only to one listening device at a time. The RS-422 standard allows for one device to communicate with many other devices simultaneously. The Vector PRO supports both serial port levels as it’s likely that the variety of electronic devices that you use will support one or the other, or both. This improves the versatility of the Vector PRO.

2.10.4 Overview of Serial Port Configuration You may configure Port A or B of the primary GPS receiver to output any combination of data that you wish. Port A can have a different configuration from Port B in terms of data message output, their data


rates, and also the baud rate of the port. This allows you to configure the ports independently, based upon your needs. For instance, if you wish to have one generalized port and one heading-only port, you may wish to configure Port A to have GGA, VTG, GSV, ZDA, and HDT all output at 1 Hz over a 9600 baud rate. You may also wish to configure Port B for HDT and ROT message output at their maximum rate of 10 Hz over a 19,200 baud rate.

The messages that you configure each port to output, and the rate of the port will be the same for both RS-232 and RS-422 interface levels. For instance, the RS-232 primary GPS receiver Port A and RS-422 primary GPS receiver Port A output the same data messages at the same baud rate. If you wish to change the baud rate or messages for the RS-422 port, this needs to be commanded through the RS-232 primary GPS Port A.

You may use both the RS-232 and the RS-422 output signals simultaneously.

2.10.5 Interfacing to a PC Computer PC computers typically use a DB9-male connector for RS-232 serial port communications. To terminate either the primary GPS receiver Port A and the secondary GPS Port A for connection to a PC serial port, connect the wires to a DB9 female connector according to the following two tables.


Note – If you need to upgrade the primary and receiver firmware in the future, you will need to load it from a PC by connecting the primary GPS Port A and secondary GPS Port B to a PC using the DB9 interface shown below.

Table 2-2 Primary GPS Port A DB9 RS-232 Interface

Pin Wire Color Signal

2 Blue Primary GPS Receiver Transmit Data RS-232

3 Black twisted with blue Primary GPS Receiver Receive Data RS-232

5 Black twisted with white

Sig. Ground

Table 2-3 Secondary GPS Port A DB9 RS-232 Interface

Pin Wire Color Signal

2 Brown Primary GPS Receiver Transmit Data RS-232

3 Black twisted with brown

Primary GPS Receiver Receive Data RS-232

5 Black twisted with white

Sig. Ground

The following figure displays the numbering scheme for a DB9 socket connector (female). The associated numbering for the plug connector (male) on a PC computer is a mirror reflection of scheme showed in this figure.


1234

679

5

8

Figure 2-25 DB9 Socket Numbering

Note - For successful communications, the baud rate of the Vector PRO serial ports must be set to match that of the devices to which they are connected. Chapter 6 describes the baud rate change command.

2.10.6 Interfacing to Other Devices When interfacing to other devices, make sure that the transmit data output from the Vector PRO is connected to the data input of the other device. The signal grounds must also be connected.

Since RS-422 is a balanced signal with positive and negative signals referenced to ground, ensure that you maintain the correct polarity. For instance, when connecting the transmit data output positive signal to the receive line of the other device, it should be connected to the receive positive terminal. The negative transmit data signal from the Vector PRO is then connected to the receive data negative input of the other device.

There’s likely not much reason to connect the receive data input of the Vector PRO to another device, unless it is able to send configuration commands to the Vector PRO. Since the Vector PRO uses proprietary NMEA 0183 commands for control over its configuration, the vast majority of electronics will not be able to configure its settings unless the other device has a terminal setting where you can manually issue commands.


2.11 Default Parameters This section outlines the default parameters of the Vector PRO. The following tables provide details on the firmware types, port settings, default NMEA messages, elevation mask, differential age mask, default differential mode, and beacon receiver settings.

Note - Any changes you make to the Vector PRO configuration need to be saved with the $JSAVE NMEA command in order to be present for a subsequent power-cycle.

Table 3-2 Firmware Applications

GPS Receiver Application 1 Application 2

Primary Attitude master firmware None

Secondary Attitude secondary f irmware

None

Table 3-3 Default Port Settings

Port Baud Rate Data Bits Parity Stop Bit Interface Level

Primary Port A 19200 8 None 1 RS-232C

Primary Port B 19200 8 None 1 RS-232C (output only)

Secondary Port A

19200 8 None 1 RS-232C

Primary Port A 19200 8 None 1 RS-422 (output only)

Primary Port B 19200 8 None 1 RS-422 (output only)

Note - The data bits, parity, and stop bit are not adjustable. They are fixed with an 8-n-1 configuration.

Table 3-4 Available Baud Rates


Baud Rates

4800

9600

19200

38400

Table 3-5 Default GPS NMEA Message Output

Port GPS NMEA Messages Update Rate

Primary A GGA, GSV, VTG, ZDA, HDT, ROT 1 Hz

Primary B GGA, GSV, VTG, ZDA, HDT, ROT 1 Hz

Secondary A

No output (idle) N/A

Table 3-6 Correction Age and Elevation Mask Defaults

Max DGPS Age Elevation Mask

1800 seconds 5?

Table 3-7 Default Differential Mode

Differential Mode

SBAS (WAAS / EGNOS)

The internal beacon module, though not the default differential correction source, operates in full automatic mode by default as shown in the following table.

Table 3-8 Beacon Operating Parameters

Default Differential Mode

MSK Rate Selection


Automatic Automatic


3. Vector PRO Overview This chapter provides a brief introduction to the Vector PRO system and some its high-level features. The remaining chapters provide more detailed information on the workings of the product.

As mentioned in the previous chapter, if you are new to GPS and SBAS, we recommend that you consult Appendix B for further information on these services and technology.

For your convenience, both the GPS and SBAS operation of the Vector PRO feature automatic operational algorithms. However, you must program the receiver inside the Vector PRO for which differential service to use as it does not automatically choose one service over the other. By default, the Vector PRO operates with SBAS corrections.

When powered, the internal GPS system performs a ‘cold start’, which involves acquiring the available GPS satellites in view and the SBAS and beacon differential services, if available. Acquisition of a GPS heading is also automatic, however, you are able to force a new heading search if needed.

If SBAS or beacon corrections are not available in your area, an external source of RTCM SC-104 differential corrections may be used. If you choose to use an external source of correction data, you will need to ensure that the external source supports RS-232 and an eight data bit, no parity, and one stop bit configuration (8-N-1) and also configure the Vector PRO for external correction operation.

3.1 GPS The following sections describe the general operation of the GPS technology within the Vector PRO.


3.1.1 Satellite Tracking The internal GPS receivers automatically search for GPS satellites, acquire the signal, and manage the associated navigation information required positioning and tracking. This is a hands-free mode of operation. Satellite acquisition quality is described as a signal to noise ratio (SNR). A higher SNR is indicative of better quality signal reception. The primary GPS receiver supplies SNR information via $GPGSV NMEA 0183 data messages that may be output through either Port A or B.

3.1.2 Positioning Accuracy The Vector PRO provides sub-meter 95% accurate positions under ideal conditions horizontally (minimum errors). Since the Vector PRO will be used in the real world, multipath signals and GPS signal blockages can reduce the level of system performance. To aid in challenging environments, the internal antennas feature a ground plane to reduce the effects of multipath.

The performance of common GPS systems is affected when using old correction data. Blockage of signals from SBAS satellites is often inevitable in real world environments, as are weak beacon signals or a noisy beacon spectrum. The COAST feature of the Vector PRO provides solace from obstruction of SBAS services and intermittent beacon reception for up to 30 to 40 minutes, depending on the amount of tolerable performance drift. After 30 minutes, our testing has shown that the Vector PRO. This feature operates by default and the COAST time is adjusted by setting the maximum differential age as needed. COAST is discussed in further detail in Section 3.4.

For example, if you wish to shorten this time period in order to minimize the effect of the divergence between COAST modeling and the true errors, the maximum COAST age can be changed to 10 minutes (600 seconds) with the following command: $JDIFF,600<CR><LF>.

The estimated positioning precision is accessible through the use of NMEA 0183 command responses as described in Chapter 6 (The GST NMEA data message). As the receiver is not able to determine


accuracy with respect to a known location in real time (this is traditionally performed in post-mission analyses), the precision numbers are relative in nature and are only approximate.

3.1.3 Update Rates The update rate of each Vector PRO NMEA message can be set independently with a maximum that is dependant upon the message type. Some messages have a 1 Hz maximum, for example, while others are 5 Hz or 10 Hz. Consult Chapter 6 for further information on individual NMEA messages.

3.2 SBAS The following sections describe the general operation and performance monitoring of the SBAS (WAAS, EGNOS, MSAS, and SNAS) demodulator within the Vector PRO. SBAS are described in further detail in Appendix A.

3.2.1 Automatic Tracking The SBAS demodulator featured within the Vector PRO automatically determines if your receiver can receive WAAS or EGNOS based upon its location. This automatic tracking allows the user to focus on other aspects of their application rather than ensuring the receiver is tracking SBAS correctly.

The SBAS demodulator features two-channel tracking that provides an enhanced ability to maintain acquisition on a SBAS satellite in regions where more than one satellite is in view. This redundant tracking approach results in more consistent acquisition of a signal when in an area where signal blockage of either satellite is possible.

Since SBAS broadcast at L-band frequency, a line of sight to the SBAS satellites is required in order to acquire the signal.


3.2.2 SBAS Performance The performance of the SBAS receiver is described in terms of a bit error rate (BER). It indicates the number of unsuccessfully decoded symbols in a moving window of 2048 symbols. Due to the use of forward error correction algorithms, one symbol is composed of two bits. The BER value for both SBAS receiver channels is available in the RD1 NMEA data message described in detail in Chapter 6.

A lower BER indicates that data is being successfully decoded with fewer errors, providing more consistent throughput. The bit error rate has a default, no-lock value of 500 or more. As the receiver begins to successfully acquire the signal, it will result in a lower bit error rate. For best operation, this value should be less than 150 and ideally less than 20.

Space-Based Augmentation Systems broadcast an ionospheric map on a periodic basis that may take up to 5 minutes to receive upon startup. The Vector PRO uses the GPS broadcast ionospheric model until it has downloaded the SBAS map, which can result in lower performance as compared to when the map has been downloaded. This will be the case for any GPS product supporting SBAS services.

Caution – Soon after startup, when the map has been downloaded, you may observe a position jump due to the potential difference between the GPS ionospheric model and the ionospheric SBAS map. To minimize the impact of this issue on your use of the Vector PRO, you may wish to wait up to five minutes before using the Vector PRO or issue the $JQUERY,GUIDE<CR><LF> message to determine if the internal GPS receiver has achieved optimum performance.


3.3 Beacon Operation The following sections describe the general operation and performance monitoring of the SBX beacon engine within the Vector PRO.

3.3.1 Tune Modes The internal beacon sensor may be operated in either Automatic or Manual beacon tune modes. In Automatic Beacon Search (ABS) mode, the receiver will identify and tune to the station providing the strongest DGPS signal. In Manual Tune mode, you specify the frequency to which the receiver will tune. NMEA 0183 commands are used to modify the configuration of the beacon sensor.

3.3.1.1 Automatic Beacon Search (ABS) Mode The Vector PRO’s internal beacon sensor operates in Automatic Beacon Search (ABS) mode by default, selecting and tuning to the most appropriate beacon without operator intervention. The beacon receiver uses its two independent beacon channels to identify and lock to DGPS beacons without interrupting the continuous flow of RTCM data to the GPS receiver.

ABS mode is ideal for navigation applications that traverse considerable distances, eliminating the need for operator intervention when transitioning from one beacon coverage zone to another. The beacon module may be manually tuned, however, this requires a NMEA command to be send to the Vector PRO as discussed in Chapter 6.

Note - We recommend that you leave the beacon receiver in the default ABS mode unless your requirements mandate operating with a specific beacon.

3.3.1.2 ABS Global Beacon Search When powered for the first time in ABS mode, the beacon sensor initiates a Global Search using both channels, examining each available DGPS beacon frequency, and recording Signal Strength (SS) measurements in units of dB?V to the Global Search Table. The


receiver uses these measured values to compute an average SS, noise floor, and to sort the frequencies in descending order of SS.

The beacon receiver’s two channels cooperatively examine the frequencies with the highest SS measurements, above the computed noise floor, to determine the station providing the strongest RTCM signal. The receiver's primary channel locks to the first identified DGPS broadcast, while the second channel continues searching in the background for superior beacon signals. If no signal is available, the Vector PRO will initiate a fresh Global Search, continuing this cycle until it finds a valid station.

3.3.1.3 ABS Background Beacon Search During the Background Search, the second beacon channel examines all frequencies at both 100 and 200 bps MSK bit rates to identify beacons possessing superior signal quality. If a DGPS broadcast is identified that exhibits a 2 dB stronger signal strength than that of the primary station, the receiver will automatically switch to this beacon. No loss of lock occurs on the primary station during the background scan.

The beacon module stores the current primary beacon in memory so that it is available upon subsequent power-up.

3.3.1.4 Manual Tracking In manual tune mode, you may select a specific frequency and bit rate for the receiver to tune, or specify the frequency only, allowing the Vector PRO to identify the correct MSK bit rate on its own. This mode of operation is most useful when working in an area where you know the frequency though not necessarily the MSK bit rate of the closest beacon.


3.3.2 Receiver Performance The Signal to Noise Ratio (SNR) best describes the Vector PRO’s internal SBX beacon receiver performance. The SNR, measured in dB, is the height of the signal above the noise floor. The higher the SNR, the more successfully the beacon receiver is demodulating the signal. You can easily monitor the SNR in the Beacon Status menu.

Table 3-1 describes the beacon receiver quality of reception with respect to the SNR reading.

Table 3-1 Beacon Receiver Performance - SNR Reading

SNR Reception Description

Approximate Data Throughput

>25 Excellent 100% data throughput 20 to 25 Very Good 100% data throughput 15 to 20 Good Good data throughput up to 100% 10 to 15 Stable Moderate to good data throughput 7 to 10 Intermittent Low data throughput

<7 No Lock No data throughput

3.4 COAST™ Technology The Vector PRO GPS technology incorporates SI-TEX COAST technology that allows it to operate with old correction data for up to 30 to 40 minutes or more without significant accuracy degradation. The feature’s performance is attributed to sophisticated algorithms that are able to anticipate how errors change during a period of correction loss.

Traditional receiver technology would experience an increasing degradation with increasing age of corrections, resulting in less than adequate performance over a shorter period of time. COAST technology provides more consistent positioning during periods when signal loss occurs, thus bridging the gap to when the signal is reacquired. This means that the Vector PRO GPS is more tolerant than


competing products to loss of SBAS or externally input RTCM SC-104 corrections.

3.5 Vector PRO Architecture The Vector PRO is comprised of two main components - hardware and software. This section provides a brief overview of the hardware and software architecture of the Vector PRO receiver in order to provide further insight into the operation of the product.

As the Vector PRO receiver supports the following services, it provides receiving capability for each.

• GPS • SBAS (WAAS and EGNOS) • Beacon

3.5.1 GPS Hardware The SI-TEX GPS engines inside the Vector PRO provide receiving capability for GPS and SBAS correction services (including WAAS, and EGNOS).

The GPS engines process GPS and SBAS signals simultaneously, devoting 2 of the primary GPS engine’s 12 parallel channels to SBAS tracking while using the remaining 10 channels for GPS. This provides effective tracking of multiple SBAS satellites if available.

3.5.2 GPS Firmware The software that operates the internal components of the Vector PRO operates within internal, low-level devices and is often referred to as firmware.

There are two types of firmware within the Vector PRO. One type of firmware drives the on-board digital signal processors (DSP) and another the ARM processors. Each of these types of firmware may be upgraded in the field through either primary GPS receiver port as new


revisions become available. The secondary GPS receiver may be upgraded through the secondary GPS receiver port.

3.5.3 GPS Applications The ARM processor of the two GPS engines inside the Vector PRO each support two simultaneous versions of firmware. In the case of the Vector PRO both the first application contains the Vector heading application. The second application is empty. The primary GPS receiver uses master vector firmware for both applications while the secondary uses slave vector firmware for both of its applications.

Note - As new firmware is released, to alleviate having to different versions of heading firmware inside the primary and secondary GPS receiver at the time of field upgrade of firmware, both application slots should be overwritten with the new version of firmware.

3.5.4 Beacon Firmware The Vector PRO’s internal beacon module incorporates its own version of firmware that controls its operation. This firmware can be updated independent of the Vector GPS firmware if needed through either primary GPS Receiver port.


4. Operation This chapter provides a brief overview of the operations of the Vector PRO and provides an introduction its the input / output interface. This will help you understand how to customize its configuration to meet your needs.

4.1 Powering the Vector PRO As described in Chapter 2, Installation, the Vector PRO is powered by connecting the red and black power leads of the power cable to an 8 to 40 VDC power source. You may wish to use an ammeter in-line of the power leads in order to verify that the system has been correctly powered. Once powered, the Vector PRO will proceed through an internal start-up sequence, however it will be ready to communicate within a few seconds. On power-up, you will see through the communications port the GSV message output at 1 Hz. This is another method to confirm that the receiver is powered and communicating correctly.

When installed such that the Vector PRO has an unobstructed view of the sky, it will provide a position within approximately 60 seconds from startup. SBAS and beacon lock require approximately 30 and 60 seconds to acquire from startup, respectively.

Note - It can take up to 5 minutes for a full ionospheric map to be received from SBAS. Optimum accuracy will be obtained once the Vector PRO is processing corrected positions using complete ionospheric information. This can be confirmed with the $JQUERY,GUIDE<CR><LF> command.

4.2 Communicating with the Vector PRO


The Vector PRO features two full-duplex serial ports, one to each GPS receiver inside the Vector PRO enclosure. In addition to the primary GPS receiver’s full-duplex Port A, it features a second half-duplex, output-only port (Port B) that may be configured through Port A.

The data message output from the primary GPS receiver’s Port A and B may be configured for a mixture of NMEA 0183, binary, and RTCM SC-104 data. The usual data output is only required NMEA data messages. The output from the secondary GPS Port A is limited to heading data only.

Note - If you require different data types to be output from the Vector PRO simultaneously you may wish to separate the data between two serial ports if this is more convenient.

Warning - In addition to heading information, you can turn position-related data on, on the secondary GPS receiver’s Port B. Please note that the position data is NOT valid and should NOT be used. This data is accessible for factory testing only.

4.2.1 NMEA 0183 Interface NMEA 0183 is a communications standard established by the National Marine Electronics Association (NMEA) and provides data definitions for a variety of navigation and related equipment. Such instruments supported include gyrocompasses, Loran receivers, echo sounders, GPS receivers, and more. NMEA functionality is virtually standard on all GPS equipment available. NMEA has an ASCII character format that allows you to read the data via terminal software on the receiving device (if possible). Some example NMEA data from the Vector PRO follows.

$GPGGA,144049.0,5100.1325,N,11402.2729,W,1,07,1.0,1027.4,M,0,M,,0100*61 $GPVTG,308.88,T,308.88,M,0.04,N,0.08,K*42 $GPGSV,3,1,10,02,73,087,54,04,00,172,39,07,66,202,54,08,23,147,48*79 $GPGSV,3,2,10,09,23,308,54,11,26,055,54,15,00,017,45,21,02,353,45*78 $GPGSV,3,3,10,26,29,257,51,27,10,147,45,,,,,,,,*74

Depending on each manufacturer’s goals for a product, they may have the need to combine data into custom messages, which allows them to


improve communication and programming efficiency. The standard NMEA standard provides for manufacturers to define their own custom, proprietary messages as required. Proprietary NMEA messages are likely to be supported only by the specific manufacturer and partners.

The Vector PRO supports a variety standard and proprietary NMEA messages. These messages are used to configure the Vector PRO and also contain the required information from the system. You may configure a selection of NMEA 0183 data messages on one port at various update rates (each message has a maximum update rate) and a different selection of NMEA 0183 messages with different rates on the other port.

Chapter 6 presents information relating to the NMEA interface of the Vector PRO. Appendix C - Resources provides contact information should you wish to purchase a copy of the NMEA 0183 standard.

4.2.2 Binary Interface Binary messages may be output from the Vector PRO along with NMEA 0183 data. Binary messages have a proprietary definition that likely will require custom software support if you wish to use it. Binary message inherently are more efficient than NMEA 0183 and would be used when you require maximum communication efficiency. Use of binary messages for most users is not recommended as the NMEA interface allows you to control the operation of the Vector PRO and also receive all necessary data regarding status and positioning information. Binary messages are described in Chapter 7.

4.2.3 RTCM SC-104 Protocol RTCM SC-104 is a standard that defines the data structure for differential correction information for a variety of differential correction applications. It has been developed by the Radio Technical Commission for Maritime services (RTCM) and has become an industry standard for communication of correction information. RTCM is a binary data protocol and is not readable via a terminal program. It appears as ‘garbage’ data on-screen since it is a binary format and not


ASCII text. The following is an example of how the RTCM data appears on-screen.

mRMP@PJfeUtNsmMFM{nVtIOTDbA^xGh~kDH`_FdW_yqLRryrDuhcB\@}N`ozbSD@O^}nrGqkeTlpLLrYpDqAsrLRrQN{zW|uW@H`z]~aGxWYt@I`_FxW_qqLRryrDCikA\@Cj]DE]|E@w_mlroMNjkKOsmMFM{PWDwW@HVEbA^xGhLJQH`_F`W_aNsmMFM[WVLA\@S}amz@ilIuPqx~_IZhTCpLLrYpdP@kOsmMFM[kVDHwVGbA^P{WWuNt_SW_yMsmMnqdrhcC\@sE^ZfC@}vJmNGAHJVhTCqLRryrdviStW@H_GbA^P{wxu[K

RTCM has various levels of detail, however the highest level is the message. RTCM defines numerous messages that contain specific information. The Vector PRO processes the C/A code for positioning and does not support more advanced methods of differential such as real-time kinematic (RTK) positioning that uses different RTCM message types. Considering this fact, the following RTCM messages are important for use with the Vector PRO.

• Type 1 and Type 9 messages, both of which contain similar information. These two messages contain pseudorange corrections and range rate corrections to each GPS satellite. • The Type 2 message contains delta differential corrections that are used when the remote receiver is using a different satellite navigation message than used by the base station. • The Type 5 message contains GPS constellation health information used for improving tracking performance of a GPS receiver • The Type 6 message contains null information, and is broadcast so that a beacon receiver demodulating the data from the broadcast does not lose lock when the beacon station has no new data to transmit.

Note - RTCM is a local area data standard. This means that when positioning with correction input to the Vector PRO from an external source or outputting corrections from the Vector PRO to another GPS receiver, performance will degrade as a function of distance from the base station. The additional degradation will depend on the difference in observed orbit and ionospheric errors between the reference station and the remote unit. A general rule of thumb would be an additional 1 m error per 100


miles. This error is often seen as a bias in positioning, resulting in a position offset. The scatter of the receiver is likely to remain close to constant.

The RTCM SC-104 data output by the Vector PRO is converted from the RTCM SC-159 data broadcast by SBAS.

Appendix C - Resources contains the contact information should you wish to purchase a copy of the RTCM SC-104 specification.

4.3 Configuring the Vector PRO All aspects of Vector PRO operation should be configured through the primary GPS Port A with the use of NMEA 0183 commands. These commands are described in the Chapter 6. The following items are user-configurable only through the primary GPS receiver).

• NMEA 0183 message interface • Tilt aiding • Tilt Sensor calibration • Magnetic aiding • Magnetometer calibration • Gyro aiding • Time constants • Level operation • Heading compensation • Configuration for pitch or roll • Antenna separation • Elevation mask • Differential timeout • Baud rates

4.4 Configuring the Data Message Output The Vector PRO primary GPS receiver features two serial port outputs referred to as A and B. GPS data messages for both ports are easily configured by sending NMEA commands to the Vector PRO receiver through Port A (the output of Port B can be configured through A). The


$JASC NMEA message discussed in Chapter 6 in details allows you to turn messages on and off as you require.

4.4.1 This Port and the Other Port When interfacing to Port A for the sake of turning data messages on or off on Port B, Port B is referred to as the ‘Other’ port.

For example, if you are communicating with the Vector PRO Port A, and wish to turn the GPGGA message on at an update rate of 5 Hz on Port B, the following command would be used.

$JASC,GPGGA,5,OTHER<CR><LF>

If you wish to turn the GPGGA message on at 5 Hz on Port A, you would issue the following command.

$JASC,GPGGA,5<CR><LF>

Consult Chapter 6 for more information on NMEA messages.


5. PocketMAX Utility PocketMAX is a freely available Windows PocketPC utility designed for use with CSI Wireless SLX and SX-1 based products, including the Vector PRO. As this utility was not designed specifically for any one product alone, it supports features not offered by every product, such as tracking of the OmniSTAR differential service and display of our Vector product’s true heading, however, the interface may be used for all I/O operations.

This software offers you the following flexibility: • Tune your beacon and WAAS receivers • Monitor beacon and WAAS reception • Configure GPS message output and port settings • Configure and monitor heading, time constants, etc. • Record various types of data PocketMAX runs on any PDA with PocketPC 2000, 2002, or 2003. CSI offers two different executables, one labeled PocketPC 2002, which works on both 2000 and 2002 operating platforms and one labeled PocketPC 2003, which works on the 2003 platform. You must have the corresponding cable for your PDA to connect to a serial port on your product. If you don’t have the latest version of PocketMAX, you can download it from the CSI Wireless website.


For a detailed discussion on the PocketMAX software, please refer to the PocketMAX Manual, also available for download from the CSI Wireless website.

Caution – It is important to note that when you are using PocketMAX, the program is doing many operations behind the scenes. This includes modifying the data output from the serial port as the program require, which is screen dependant. When you close PocketMAX, it will give you a message confirming the


current settings. It will then ask you if you want to proceed and save these settings or go back and change them. Once you have the settings configured properly for you, it is imperative to let the program close completely on its own before you disconnect or power down the receiver. This may take up to 10 seconds. If this is not performed, the receiver will not be configured as you feel it should, and can output a mixture of binary and NMEA data.

6. NMEA 0183 Messages This chapter identifies the selection of standard and proprietary NMEA 0183 messages for the Vector PRO receiver.

Note – All NMEA commands must be sent through the primary GPS Port A RS-232 port. From this port, you can configure the settings of the Vector PRO and also the data messages output from primary GPS Port A and B. The secondary GPS may be configured for HDT and HPR message output only, using appropriate commands.

6.1 NMEA Message Elements NMEA 0183 messages have a common structure, consisting of a message header, data fields, checksum, and carriage return/line feed message terminator. An example NMEA sentence follows.

$XXYYY,zzz,zzz,zzz…*xx<CR><LF>

The components of this generic NMEA message example are displayed in the following table.


Table6-1 NMEA Message Elements

Element Description

$ Message header character XX NMEA Talker field. GP indicates a GPS

talker YYY Type of GPS NMEA Message zzz Variable Length Message Fields *xx Checksum

<CR> Carriage Return <LF> Line Feed

Null, or empty fields occur when no information is available for that field.

6.2 PocketMAX CSI Wireless offers a configuration program designed for Windows PocketPC software that runs on PocketPC 2000, 2002 and 2003 platforms. It can be used to configure and monitor your differential source, GPS messages and it also records various types of data. It is available for download from CSI’s website. This utility is discussed in the PocketMAX Manual and a screen-shot is shown in the following figure.

Caution – It is important to note that when you are using PocketMAX, the program is doing many operations behind the scenes. This includes modifying the data output from the serial port as the program require, which is screen dependant. When you close PocketMAX, it will give you a message confirming the current settings. It will then ask you if you want to proceed and save these settings or go back and change them. Once you have the settings configured properly for you, it is imperative to let the program close completely on its own before you disconnect or power down the receiver. This may take up to 10 seconds. If this is not performed, the receiver will not be configured as you feel it should, and can output a mixture of binary and NMEA data.


Figure 6-1 PocketMAX Screen Capture

6.3 General Commands This section presents various commands relating to the general operation and configuration of the Vector PRO.

The following table provides a brief description of the general commands supported by the Vector PRO.


Table 6-1 General Commands

Message Description

$JASC,Dx Command to turn on diagnostic information. $JAIR This is a command to place the receiver into ‘AIR’ mode where the

receiver will respond better to the high dynamics associated with airborne applications.

$JASC,VIRTUAL This command is used to output RTCM data fed into the other port, through the current port

$JASC,RTCM This command is used to output RTCM data from the SBAS demodulator $JALT This command is used to set the altitude aiding mode of the Vector PRO $JAPP This command is used to query the current applications and also choose

the current application. $JBAUD Baud rate change command for the Vector PRO. $JCONN Virtual circuit command used to interface to the internal beacon receiver

or communicate with the menu system microprocessor. $JDIFF This command is used to set the differential mode.

$JK This command is used to subscribe certain features of use of the Vector PRO.

$JPOS This command is used to provide the Vector PRO with a seed position to acquire a SBAS signal more quickly upon start-up. This is not normally needed.

$JQUERY,GUIDE This command is used to poll the Vector PRO for its opinion on whether or not it is providing suitable accuracy after the both SBAS and GPS have been acquired (up to 5 min)

$JRESET This command is used to reset the configuration of the Vector PRO. $JSAVE This command is used to save the configuration of the Vector PRO. $JSHOW This command is used to query the Vector PRO for its configuration.

$JT This command is used to poll the Vector PRO for its receiver type $JBIN This command is used to turn on the various binary messages supported

by the Vector PRO $JI This command is used to get information from the Vector PRO such as its

serial number and firmware version information

The following subsections provide detailed information relating to the use of each command.


Note - Please ensure that you save any changes that you wish to survive beyond the current power-up by using the $JSAVE command and wait for the ‘$> Save Complete’ response.

6.3.1 $JASC,D1 This command allows you to adjust the output of the RD1 diagnostic information message from the Vector PRO.

This command has the following structure.

$JASC,D1,r[,OTHER]<CR><LF>

Currently, only the RD1 message is currently defined, with x = 1. The message status variable ‘r’ may be one of the following values.

r Description

0 ON 1 OFF

When the ‘,OTHER’ data field is specified (without the square brackets), this command will enact a change in the RD1 message on the other port.

6.3.2 $JAIR This command allows you to place the primary GPS engine within the Vector PRO into AIR mode HIGH, where the receiver is optimized for the high dynamic environment associated with airborne platforms. JAIR defaults to normal (NORM) and this setting is recommended for most applications. Turning AIR mode on to HIGH is not recommended for Vector PRO operation.

The format of this command follows.

$JAIR,r<CR><LF>

Where feature status variable, ‘r’, may be one of the following values.


r Description

0 NORM 1 HIGH

The Vector PRO will reply with the following response.

$>

6.3.3 $JASC,VIRTUAL When using an external correction source, this command is used to ‘daisy chain’ RTCM data from being input from one port and output through the other. For example, if RTCM is input on Port B, this data will correct the position and also be output through Port A. The Vector PRO acts as a pass-through for the RTCM data. Either port may be configured to accept RTCM data input and this command then allows the opposite port to output the RTCM data.

To configure the Vector PRO to output RTCM data on the current port from data input on the other port, issue the following command.

$JASC,VIRTUAL,r<CR><LF>

To configure the Vector PRO to output RTCM data on the other port from RTCM data input on the current port, issue the following command.

$JASC,VIRTUAL,r,OTHER<CR><LF>

Where the message status variable, ‘r’, may be one of the following.

r Description

0 ON 1 OFF



$>

6.3.4 $JALT This command turns altitude aiding on or off for the Vector PRO module. When set to on, altitude aiding uses a fixed altitude instead of using one satellite’s observations to calculate the altitude. The advantage of this feature, when operating in an application where a fixed altitude is acceptable, is that the extra satellite’s observations can be used to betterment of the latitude, longitude, and time offset calculations, resulting in improved accuracy and integrity. Marine markets, for example, may be well suited for use of this feature, however, it’s not normally required for Vector PRO operation.

This command has the following layout.

$JALT,c,v[,GEOID] <CR><LF>

Where feature status variable, ‘c’, and threshold variable, ‘v’, may be one of the following.

c Description

NEVER This is the default mode of operation where altitude aiding is not used.

SOMETIMES Setting this feature to SOMETIMES allows the receiver to use altitude aiding, dependent upon the PDOP threshold, specified by ‘v’

ALWAYS Setting this feature to ALWAYS allows the receiver to use altitude aiding regardless of a variable. In this case, you may specify the ellipsoidal altitude, ‘v’ that the receiver should use. Optionally, if you specify the ‘,GEOID’ field, the receiver will use the GEOID as its reference.



$>

6.3.5 $JLIMIT This command is used to change the threshold of estimated horizontal performance for which the DGPS position LED is illuminated. The default value for this parameter is a conservative 10.0 meters. This command has the following format.

$JLIMIT,limit<CR><LF>

Where ‘limit’ is the new limit in meters.

The receiver will respond with the following message.

$>

If you wish to verify the current $JLIMIT threshold, the response to the $JSHOW command provides this information.

6.3.6 $JAPP This command allows you to request the Vector PRO for the currently installed applications and to choose which application to use. Both internal GPS engines each have two copies of their firmware in both application slots. This ensures that the application is not accidentally changed such that the receiver fails to function correctly.

To poll the receiver for the current applications, send the following message.

$JAPP<CR><LF>

There are no data fields to specify in this message. The receiver will respond with the following message.

$>JAPP,current,other


Where ‘current’ indicates the current application in use and ‘other’ indicates the secondary application that is not in use currently. To change from the current application to the other application (when a two applications are present), issue the following command.

$JAPP,OTHER<CR><LF>

or

$JAPP,app<CR><LF>

Where ‘app’ may be one of the following by name.

app Description

ATTITUDEM Attitude master firmware ATTITUDES Attitude secondary

firmware

Note - Other derivatives of the $JAPP command are the $JAPP,1<CR><LF> and $JAPP,2<CR><LF> commands that can be used to set the Vector PRO to use the first and second application. It’s best to follow up the sending of these commands with a $JAPP query to see which application is 1 or 2. These two commands are best used when upgrading the firmware inside the Vector PRO, as the firmware upgrading utility uses the application number to designate which application to overwrite.

Note - When running an application, you can issue a $JI command to determine the version of that application.

6.3.7 $JBAUD This command is used to configure the baud rates of the Vector PRO.



$JBAUD,r[,OTHER] <CR><LF>

Where ‘r’ may be one of the following baud rates.

Baud Rates

4800 9600 19200 38400

When this command has been issued without the ‘,OTHER’ data field, the baud rate of the current port will be changed accordingly. When the ‘,OTHER’ data field is specified (without the square brackets), a baud rate change will occur for the other port.


$>

6.3.8 $JCONN This command is used to create a virtual circuit between the A and B port, if needed. This allows you to communicate through the Vector PRO from Port A or B to the opposite port.

The virtual circuit command has the following form.

$JCONN,p<CR><LF>

Where the connection type, ‘p’, may be one of the following.

p Description

AB Specify ‘AB’ in order to connect the A port to the B port

X Once a virtual circuit has been established, to remove the virtual circuit, specify ‘X’ in this command to return the current port to normal


6.3.9 $JDIFF This command is used to change the differential mode of the Vector PRO receiver. The default differential mode is SBAS (WAAS).

The structure of this command follows.

$JDIFF,diff<CR><LF>

Where the differential mode variable, ‘diff’, has one of the following values.

diff Description

OTHER Specifying OTHER instructs the Vector PRO to use external corrections input through the opposite port from which you are communicating

BEACON Specifying BEACON instructs the Vector PRO to use corrections from the internal SBX beacon engine

WAAS Specifying WAAS instructs the Vector PRO to use SBAS corrections

NONE In order for the Vector PRO to operate in autonomous mode, the NONE argument may be specified in this command.

6.3.10 $JK This command is used by the Vector PRO to enable subscriptions for various features.

This command will have the following format.

$JK,x…<CR><LF>

Where ‘x…’ is the subscription key provided by SI-TEX and is 10 characters in length.

If you send the $JK command without a subscription key as follows, it will return the expiry date of the subscription.

$JK<CR><LF>


Reply.

$>JK,12/31/2003,1

6.3.11 $JPOS This command is used to speed up the initial acquisition when changing continents with the Vector PRO (for example, powering it for the first time in Europe after it has been tested in Canada). This will allow it to begin the acquisition process for the closest SBAS spot beams. This will save some time with acquisition of the SBAS service, however, use of this message is typically not required due to the quick overall startup time of the Vector PRO receiver.


$JPOS,lat,lon<CR><LF>

Where ‘lat’ and ‘lon’ have the following requirements.

Position Component

Description

lat Latitude component must be entered in decimal degrees. This component does not have to be more accurate than half a degree.

lon Longitude component must be entered in decimal degrees. This component does not have to be more accurate than approximately half a degree.

Note - this command is not normally required for operation of the Vector PRO module.

6.3.12 $JQUERY,GUIDE This command is used to poll the Vector PRO for its opinion on whether or not it is providing suitable performance after the both SBAS and GPS have been acquired (up to 5 min). This feature takes into consider the


download status of the SBAS ionospheric map and also the carrier phase smoothing of the GPS.

This command has the following format.

$JQUERY,GUIDE<CR><LF>

If the Vector PRO is ready for use with navigation or positioning with optimum performance, it will return the following message.

$>JQUERY,GUIDE,YES<CR><LF>

Otherwise, it will return the following message.

$>JQUERY,GUIDE,NO<CR><LF>

6.3.13 $JRESET This command is used to reset the Vector PRO GPS engines to their default operating parameters.

This message has the following format.

$JRESET<CR><LF>

6.3.14 $JSAVE Sending this command is required after making changes to the operating mode of the Vector PRO in order to ensure the changes are present for the subsequent power cycle.

$JATT commands do not require a $JSAVE command to be issued subsequently as their changes are automatically saved.


$JSAVE<CR><LF>


The Vector PRO will reply with the following two messages. Ensure that the receiver indicates that the save process is complete before turning the receiver off or changing the configuration further.

$> Saving Configuration. Please Wait...

$> Save Complete

No data fields are required. The receiver will indicate that the configuration is being saved and will notify you when the save is complete.

6.3.15 $JSHOW This command is used to poll the Vector PRO for its current configuration.


$JSHOW[,subset] <CR><LF>

Using the $JSHOW command without the optional ‘,subset’ field will provide a complete response from the receiver. An example of this response follows.


$>JSHOW,BAUD,9600 (1) $>JSHOW,BAUD,9600,OTHER (2) $>JSHOW,ASC,GPGGA,1.0,OTHER (3) $>JSHOW,ASC,GPVTG,1.0,OTHER (4) $>JSHOW,ASC,GPGSV,1.0,OTHER (5) $>JSHOW,ASC,GPGST,1.0,OTHER (6) $>JSHOW,ASC,D1,1,OTHER (7) $>JSHOW,DIFF,WAAS (8) $>JSHOW,ALT,NEVER (9) $>JSHOW,LIMIT,10.0 (10) $>JSHOW,MASK,5 (11) $>JSHOW,POS,51.0,-114.0 (12) $>JSHOW,AIR,AUTO,OFF (13) $>JSHOW,FREQ,1575.4200,250 (14) $>JSHOW,AGE,1800 (15)

This example response is summarized in the following table.

Line Description

1 This line indicates that the current port is set to a baud rate of 9600 2 This line indicates that the other port is set to a baud rate of 9600 3 This line indicates that GPGGA is output at a rate of 1 Hz from the other port 4 This line indicates that GPVTG is output at a rate of 1 Hz from the other port 5 This line indicates that the GPGSV is output at a rate of 1 Hz from the other

port 6 This line indicates that GPGST is output at a rate of 1 Hz from the other port 7 This line indicates that D1 is output at a rate of 1 Hz from the other port 8 This line indicates that the current differential mode is WAAS 9 This line indicates the status of the altitude aiding feature 10 This line indicates the threshold of estimated differential performance that

allows the green DGPS LED to illuminate 11 This line indicates the current elevation mask cutoff angle, in degrees 12 This line indicates the current seed position used for startup, in decimal

degrees 13 This line indicates the current status of the AIR mode 14 This line indicates the current frequency of the L-band receiver 15 This line indicates the current maximum acceptable differential age in

seconds


When issuing this command with the optional ‘,subset’ data field (without the square brackets), a one-line response is provided. The subset field may be either CONF or GP.

When CONF is specified for ‘subset’, the following response is provided.

$>JSHOW,CONF,N,0.0,10.0,5,A,60W

This response is summarized in the following table.

Message Component

Description

$>JSHOW,CONF Message header

N ‘N’ indicates no altitude aiding 0.0 ‘0.0’ indicates the aiding value, if specified (either specified

height or PDOP threshold) 10.0 Residual limit for the $JLIMIT command

5 Elevation mask cutoff angle, in degrees A AIR mode indication 60 Maximum acceptable age of correction data in seconds W Current differential mode, ‘W’ indicates WAAS mode.

When GP is specified for ‘subset’, the following is an example response provided.

$>JSHOW,GP,GGA,1.0

This response will provide the >$JSHOW,GP message header, followed by each message currently being output through the current port and also the update rate for that message.

6.3.16 $JT This command displays the type of receiver engine within the Vector PRO and has the following format.

$JT<CR><LF>


The receiver will return the following response, indicating that the receiver is an SX1a (‘a’ for attitude system) when in.

$>JT,SX1a

6.3.17 $JI This command displays Vector PRO receiver information. It has the following format

$JI<CR><LF>

The receiver will reply with the following message.

$>JI,11577,1,5,11102002,01/01/1900,01/01/3003,1.1,38

This command is summarized in the following table.

Message Component

Description

11577 This field provides the serial number of the GPS engine

1 This field is the fleet number 5 This is the hardware version

11102002 This field is the production date code 01/01/1900 This field is the subscription begin date 1/01/3003 This field is the Subscription expiration date

1.1 This field is the ARM version 38 This field is the DSP version

6.3.18 $JBIN This command allows you to request the output of the various binary messages. These latter two messages contain all information required for post processing.

This message has the following structure.

$JBIN,msg,r


Where ‘msg’ is the message name and ‘r’ is the message rate as shown in the table below.

msg r (Hz) Description

Bin1 5, 1, 0, or .2 Binary GPS position message. Bin2 5, 1, 0, or .2 Binary message containing GPS DOP’s. Bin80 1 or 0 Binary message containing SBAS information. Bin95 1 or 0 Binary message containing ephemeris information. Bin96 1 or 0 Binary message containing code and carrier phase

information. Bin97 5, 1, 0, or .2 Binary message containing process statistics Bin98 1 or 0 Binary message containing satellite and almanac

information. Bin99 5, 1, 0, or .2 Binary message containing GPS diagnostic information.


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6.4 GPS Commands This section describes the selection of commands specific to the configuration and operation of the Vector PRO.

The following table provides a brief description of the commands supported by the GPS engine for its configuration and operation.

Table 6-3 GPS Commands

Message Description

$JASC,GP This command is used to configure the NMEA message output of the GPS engine

$JAGE A command used to configure the maximum age of DGPS corrections $JOFF This command is used to turn off all data output by the GPS engine

$JMASK This command allows you to modify the cut-off angle for tracking of GPS satellites

$J4STRING This command allows you to configure the GPS for output of the GPGGA, GPGSA, GPVTG, and GPZDA messages at a specific baud rate


$JSMOOTH This command is used to change the carrier smoothing interval from long to short.



6.4.1 $JASC Using this command, you may turn GPS data messages on at a particular update rate or turn them off. When turning messages on, you have the choice of various update rates available, depending on what your requirements are.


$JASC,msg,r[,OTHER]<CR><LF>

Where ‘msg’ is the name of the data message and ‘r’ is the message rate, as shown in the table below. Sending the command without the optional ‘,OTHER’ data field will enact a change on the current port.

Sending a command with a zero value for the ‘r’ field turns off a message.


msg r (Hz) Description

GPGGA 5, 1, 0, or .2 Global Positioning System Fix Data GPGLL 5, 1, 0, or .2 Geographic Position - Latitude/Longitude GPGSA 1 or 0 GNSS (Global Navigation Satellite System) DOP and Active

Satellites GPGST 1 or 0 GNSS Pseudorange Error Statistics GPGSV 1 or 0 GNSS Satellites in View GPRMC 5, 1, 0, or .2 Recommended Minimum Specific GNSS Data GPRRE 1 or 0 Range residual message GPVTG 5, 1, 0, or .2 Course Over Ground and Ground Speed GPZDA 5, 1, 0, or .2 Time and Date

HDT 10, 5, 1, 0, or 0.2 RTK-derived GPS Heading ROT 10, 5, 1, 0, or 0.2 RTK-derived GPS rate of turn INTLT 1 or 0 Internal tilt sensor measurement HPR 10, 5, 1, 0, or 0.2 Proprietary message containing heading and roll or pitch

When the ‘,OTHER’ data field is specified (without the square brackets), this command will enact a change on the other port.


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6.4.2 $JAGE This command allows you to choose the maximum allowable age for correction data. The default setting for the Vector PRO is 1800 seconds, however, you may change this value as you feel appropriate. This setting inherently defines how long a receiver should coast using the COAST feature.

Using COAST, the Vector PRO is able to use old correction data for extended periods of time. If you choose to use a maximum correction age older than 1800 seconds, we recommend that you consider testing the receiver to ensure that the new setting meets your requirements as accuracy will slowly drift with increasing time.



$JAGE,age<CR><LF>

Where maximum differential age timeout variable, ‘age’, may be a value from 6 to 8100 seconds.


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6.4.3 $JOFF This command allows you to turn off all data messages being output through the current or other port, including any binary messages.

This command has the following definition.

$JOFF[,OTHER]<CR><LF>

When the ‘,OTHER’ data field is specified (without the square brackets), this command will turn on the four NMEA messages on the other port.

There are no variable data fields for this message. The Vector PRO will reply with the following response.

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6.4.4 $JMASK This command allows you to change the elevation cutoff mask angle for the GPS engine. Any satellites below this mask angle will be ignored, even if available. The default angle is 5 degrees, as satellites available below this angle will have significant tropospheric refraction errors.

This message has the following format.

$JMASK,e<CR><LF>


Where the elevation mask cutoff angle, ‘e’, may be a value from 0 to 60 degrees.


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6.4.5 $J4STRING This command allows the GPGGA, GPVTG, GPGSA, and GPZDA messages to all be output with the issue of a single command. The output rate of each message is limited to 1 Hz, however, you may choose the set the baud rate of the current or other port at the same time.

This command has the following definition.

$J4STRING[,r][,OTHER] <CR><LF>

Where ‘r’ may be one of the following baud rates.

Baud Rates

4800 9600

When the ‘,OTHER’ data field is specified (without the square brackets), this command will turn on the four NMEA messages on the other port.


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6.4.6 $JSMOOTH There is a new command, $JSMOOTH that enables the user to change the carrier smoothing interval between 15 minutes and 5 minutes. This command was designed to offer the user flexibility for tuning in different environments. You may find a slight improvement in positioning


performance using either the short or long smoothing interval depending on your multipath environment. The default for this command is 15 minutes or LONG. To change the smoothing interval to 5 minutes or SHORT, use the following command.

$JSMOOTH,SHORT<CR><LF>

If you wish to change the smoothing interval to 15 minutes or LONG, use the following command.

$JSMOOTH,LONG<CR><LF>

If you wish to request the status of this message, send the following command. The status of this command is also output in the $JSHOW message.

$JSMOOTH<CR><LF>

Note - If you are unsure of the best value for this setting, it’s best to be conservative and leave it at the default setting of LONG (15 minutes).

6.5 SBAS Commands This section details the NMEA messages accepted by the internal SBAS engine of the Vector PRO system.

The following table provides a brief description of the commands supported by the SBAS demodulator for its control and operation.


Table 6-4 SBAS Commands

Message Description

$JWAASPRN This message is used to reconfigure the WAAS PRN numbers for use with other Space Based Augmentation Systems (SBAS)

$JGEO This command is used to poll the WAAS demodulator for information relating to your current location and WAAS satellites

$JASC,D1 This command is used to poll the Vector PRO for SBAS diagnostic information

$JASC,RTCM This feature allows you to configure the Vector PRO to output RTCM data from the WAAS demodulator



6.5.1 $JWAASPRN This command allows you to both poll the Vector PRO’s internal SBAS demodulator PRN’s in memory, and change them, if desired.

To poll the receiver for the current SBAS PRN’s, send the following message.

$JWAASPRN<CR><LF>

There are no data fields to specify in this message. The receiver will respond with the following message.

$>JWAASPRN,prn1,prn2

Where ‘prn1’ indicates the first PRN number and ‘prn2’ indicates the second PRN number. The PRN numbers for WAAS are 122 and 134.


EGNOS is currently using PRN 120 but also has PRN 131. The SBAS PRN numbers are described in more detail in Appendix B.

To manually change the current PRN numbers, the following message should be used.

$JWAASPRN[,sv1[,sv2]] <CR><LF>

Where ‘sv1’ is the PRN number of the first SBAS satellite and ‘sv2’ is the PRN number of the second SBAS satellite. ‘sv1’ or both ‘sv1’ and ‘sv2’ may be specified.


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If you wish to return the unit to automatic SBAS tracking, the following command should be sent to the receiver.

$JWAASPRN,AUTO <CR><LF>


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6.5.2 $JGEO This message is used to display information related to the current frequency of SBAS, and its location in relation to the Vector PRO’s antenna. Knowing the location of the SBAS satellites can be very useful when troubleshooting a reception problem, as in some geographic regions, these satellites may appear quite low on the horizon.

To query the Vector PRO for the currently used SBAS satellite information, use the following query.

$JGEO<CR><LF>

The receiver will respond with the following data message.


$>JGEO,Sent=1575.4200,Used=1575.4200,PRN=prn,Lon=lon,El=ele,Az=az

This message response is summarized in the following table.

Data Field Description

$>JGEO Message header. Sent=1575.4200 Frequency sent to the digital signal processor Used=1575.4200 Frequency currently used by the digital signal processor

PRN=prn WAAS satellite PRN number Lon=-lon Longitude of the satellite

El=ele Elevation angle from the primary GPS antenna to the WAAS satellite, referenced to the horizon.

Az=az Azimuth from the primary GPS antenna to the WAAS satellite, referenced to the horizon.

To monitor this information for dual SBAS satellites, add the ‘,ALL’ variable to the $JGEO message as follows.

$JGEO[,ALL] <CR><LF>

This will result in the following output messages.

$>JGEO,Sent=1575.4200,Used=1575.4200,PRN=122,Lon=-54,El=9.7,Az=114.0

$>JGEO,Sent=1575.4200,Used=1575.4200,PRN=134,Lon=178,El=5.0,Az=252.6

As can be seen from this output, the first message is identical to the output from the $JGEO query, however, the second message provides information on the WAAS satellite not being currently used. Both outputs follow the format in the previous table for the $JGEO query.


6.5.3 $JASC,D1 This command is used to request SBAS diagnostic information from the Vector PRO. The following section details the contents of this message.

To command the Vector PRO to output the diagnostic information message for the currently used SBAS satellites at a rate of 1 Hz, use the following query.

$JASC,D1,1[,OTHER]<CR><LF>

The receiver will respond with the following data message.

$>

Setting the update rate to zero as follows will turn off this message.

$JASC,D1,0<CR><LF>

6.5.4 $JASC,RTCM This command allows you to configure the Vector PRO to output RTCM corrections from SBAS through either Port A or B. The correction data output is RTCM SC-104 even though SBAS uses a different over-the-air protocol (RTCA SC-159).

To have the Vector PRO unit output RTCM corrections, send the following command to the Vector PRO.

$JASC,RTCM,r[,OTHER]<CR><LF>

The message status variable ‘r’ may be one of the following values.

r Description

0 ON 1 OFF


When the ‘,OTHER’ data field is specified (without the square brackets), this command will turn RTCM data on or off on the other port.


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6.6 Data Messages The following subsections describe the NMEA data messages listed in Table 6-5 in detail.

Table 6-5 Data Messages

Message

Max Rate Description

GPGGA 5 Hz Global Positioning System Fix Data GPGLL 5 Hz Geographic Position - Latitude/Longitude GPGSA 1 Hz GNSS (Global Navigation Satellite System) DOP and Active

Satellites GPGST 1 Hz GNSS Pseudorange Error Statistics GPGSV 1 Hz GNSS Satellites in View GPRMC 5 Hz Recommended Minimum Specific GNSS Data GPRRE 1 Hz Range residual message GPVTG 5Hz Course Over Ground and Ground Speed GPZDA 5 Hz Time and Date

RD1 1 Hz SBAS diagnostic information (proprietary NMEA message) $PCSI,1 1 Hz This is a proprietary beacon status message

HDT 10 Hz This message provides the true heading ROT 10 Hz This message provides rate of turn information HPR 10 Hz This is a proprietary message with time, true heading, and pitch

or roll

Note - For clarity, each data message will be presented on a new page.


6.6.1 GGA Data Message The GGA message contains detailed GPS position information, and is the most frequently used NMEA data message. In Table 6-6, the GGA data message is broken down into its components. This message takes the following form.

$GPGGA,hhmmss.ss,ddmm.mmmm,s,dddmm.mmmm,s,n,qq,pp.p,saaaaa.aa,M,?xxxx.xx,M,sss,aaaa*cc<CR><LF>

Table 6-6 GGA Data Message Defined

Field Description

hhmmss.ss UTC time in hours, minutes, seconds of the GPS position ddmm.mmmmm Latitude in degrees, minutes, and decimal minutes

s s = N or s = S, for North or South latitude dddmm.mmmmm Longitude in degrees, minutes, and decimal minutes

s s =E or s = W, for East or West longitude n Quality indicator, 0 = no position, 1 = undifferentially corrected position, 2

= differentially corrected position, 9= position computed using almanac qq Number of satellites used in position computation

pp.p HDOP =0.0 to 9.9 saaaa.aa Antenna altitude

M Altitude units, M = meters ?xxxx.xx Geoidal separation (needs geoidal height option)

M Geoidal separation units, M = meters sss Age of differential corrections in seconds aaa Reference station identification *cc Checksum

<CR><LF> Carriage return and line feed


6.6.2 GLL Data Message The GLL message contains Latitude and Longitude. In Table 6-7, the GLL data message is broken down into its components. This message has the following format.

$GPGLL,ddmm.mmmm,s,dddmm.mmmm,s,hhmmss.ss,s,v*cc<CR><LF>

Table 6-7 GLL Data Message Defined

Field Description

ddmm.mmmmm Latitude in degrees, minutes, and decimal minutes s s = N or s = S, for North or South latitude

dddmm.mmmmm Longitude in degrees, minutes, and decimal minutes s s = E or s = W, for East or West longitude

hhmmss.ss UTC time in hours, minutes, and seconds of GPS position

s Status, s = A = valid, s = V = invalid v Mode Indicator, A = autonomous, D = Differential, E =

Estimated (dead reckoning), M = manual input, S = simulator, and N = data not valid

*cc Checksum <CR><LF> Carriage return and line feed


6.6.3 GSA Data Message The GSA message contains GPS DOP and active satellite information. Only satellites used in the position computation are present in this message. Null fields are present when data is unavailable due to the number of satellites tracked. Table 6-8, breaks down the GSA message into its components. This message has the following format.

$GPGSA,a,b,cc,dd,ee,ff,gg,hh,ii,jj,kk,mm,nn,oo,p.p,q.q,r.r *cc<CR><LF>

Table 6-8 GSA Data Message Defined

Field Description

a Satellite acquisition mode M = manually forced to 2D or 3D, A = automatic swap between 2D and 3D

b Position mode, 1 = fix not available, 2 = 2D fix, 3 = 3D fix cc to oo Satellites used in the position solution, a null field occurs if a channel is unused

p.p Position Dilution of Precision (PDOP) = 1.0 to 9.9 q.q Horizontal Dilution of Precision (HDOP) = 1.0 to 9.9 r.r Vertical Dilution of Precision (VDOP) = 1.0 to 9.9 *cc Checksum



6.6.4 GST Data Message The GST message contains Global Navigation Satellite System (GNSS) psuedorange error statistics. Table 6-9, breaks down the GST message into its components. This message has the following format.

$GPGST,hhmmss.ss,a.a,b.b,c.c,d.d,e.e,f.f,g.g *cc<CR><LF>

Table 6-9 GST Data Message Defined

Field Description

hhmmss.ss UTC time in hours, minutes, seconds of the GPS position a.a Root mean square (rms) value of the standard deviation of the range inputs to

the navigation process. Range inputs include pseudoranges and differential GNSS (DGNSS) corrections

b.b Standard deviation of semi-major axis of error ellipse (meters) c.c Standard deviation of semi-minor axis of error ellipse (meters) d.d Orientation of semi-major axis of error ellipse (degrees) e.e Standard deviation of latitude error (meteers) f.f Standard deviation of longitude error (meters) g.g Standard deviation of altitude error (meters) *cc Checksum



6.6.5 GSV Data Message The GSV message contains GPS satellite information. Null fields occur where data is not available due to the number of satellites tracked. Table 6-10 breaks down the GSV data message into its components. This message has the following format.

$GPGSV,t,m,n,ii,ee,aaa,ss,…ii,ee,aaa,ss,*cc<CR><LF>

Table 6-10 GSV Data Message Defined

Field Description

t Total number of messages m Message number, m = 1 to 3 n Total number of satellites in view ii Satellite number

ee Elevation in degrees, ee = 0 to 90 aaa Azimuth (true) in degrees, aaa = 0 to

359

ss SNR (dB) + 30, ss = 0 to 99 *cc Checksum



6.6.6 RMC Data Message The RMC message contains recommended minimum specific GPS data. Table 6-11 breaks down the RMC data message into its components. This message has the following format.

$GPRMC,hhmmss.ss,a,ddmm.mmm,n,dddmm.mmm,w,z.z,y.y,ddmmyy,d.d,v,w *cc<CR><LF>

Table 6-11 RMC Data Message Defined

Field Description

hhmmss.ss UTC time in hours, minutes, seconds of the GPS position

a Status is valid if a = A, status is invalid if a = V ddmm.mmmmm Latitude in degrees, minutes, and decimal minutes

n S = N or s = S, for North or South latitude

dddmm.mmmmm Longitude in degrees, minutes, and decimal minutes w S = E or s = W, for East or West longitude z.z Ground speed in knots y.y Track made good, referenced to true north

ddmmyy UTC date of position fix in day, month, year d.d Magnetic Variation in degrees v Variation sense v = E = East, v = W = West w Mode Indicator, A = autonomous, D = Differential, E =

Estimated (dead reckoning), M = manual input, S = simulator, and N = data not valid



6.6.7 RRE Data Message The RRE message contains the satellite range residuals and estimated position error. Table 6-12 breaks down the RRE data message into its components. This message has the following format.

$GPRRE,n,ii,rr…ii,rr,hhh.h,vvv.v *cc<CR><LF>

Table 6-12 RRE Data Message Defined

Field Description

n Number of satellites used in position computation

ii Satellite number rr Range residual in meters

hhh.h Horizontal position error estimate in meters vvv.v Vertical position error estimate in meters *cc Checksum



6.6.8 VTG Data Message The VTG message contains velocity and course information. Table 6-13 breaks down the VTG data message into its components. This message has the following format.

$GPVTG,ttt,c,ttt,c,ggg.gg,u,ggg.gg,u,v*cc<CR><LF>

Table 6-13 VTG Data Message Defined

Field Description

ttt True course over ground, ttt = 000 to 359, in degrees c True course over ground indicator, c = T always ttt Magnetic course over ground, ttt = 000 to 359, in degrees (output with magnetic

model option only) c Magnetic course over ground Indicator, always c = M

ggg.gg Speed over ground, 000 to 999 knots u Speed over ground units, u = N = Nautical mile/h

ggg.gg Speed over ground, 000 to 999 km/h u Speed over ground units, u = K = kilometer/h v Mode Indicator, A = autonomous, D = Differential, E = Estimated (dead

reckoning), M = manual input, S = simulator, and N = data not valid *cc Checksum



6.6.9 ZDA Data Message The ZDA message contains Universal Time information. Table 6-14 breaks down the ZDA data message into its components. This message has the following format.

$GPZDA,hhmmss.ss,dd,mm,yyyy,xx,yy*cc<CR><LF>

Table 6-14 ZDA Data Message Defined

Field Description

hhmmss.ss UTC time in hours, minutes, seconds of the GPS position

dd Day, dd = 0 to 31 mm Month, mm = 1 to 12

yyyy Year xx Local zone description in hours, xx = -13 to 13 yy Local zone description in minutes, yy = 0 to 59 *cc Checksum



6.6.10 RD1 Data Message The RD1 message contains diagnostic information for SBAS operation. Table 6-15 breaks down the RD1 data message into its components. This message has the following format.

$RD1,SecOfWeek,WeekNum,FreqMHz,DSPLocked,BER-BER2,AGC,DDS,Doppler,DSPStat,ARMStat,DiffStatus,NavCondition *cc<CR><LF>

Table 6-15 RD1 Data Message Defined

Field Description

SecOfWeek The second of GPS week (may be a couple of seconds old) WeekNum The GPS week number FreqMHz The L-band frequency in MHz (1475.4200 is used for SBAS)

DSPLocked 1 if DSPStat = 1B or 1F BER-BER2 Bit error rate - bit error rates are given for both SBAS satellites being tracked

AGC L-band Signal strength DDS 0.0 for SBAS

Doppler 0 for SBAS DSPStat A status bit mask for the DSP tracking of SBAS ARMStat A status bit mask for the ARM GPS solution DiffStatus The SBAS PRN of the satellite in use

NavCondition A series of hex character fields, which is read from right to left, with each field representing the number of GPS satellites satisfying a certain condition, all of which conditions are required if the satellite is to be used in the solution


The following table describes the DSP status. The DSP status should be 17, 1B, or 1F when SBAS tracking has been achieved.


Field Description

01 Carrier lock 02 BER is ok on at least one SBAS satellite 04 Frame synchronization has been achieved on the second

satellite 08 Frame synchronization has been achieved on the first

satellite 10 Carrier lock

The following table describes the ARM status.

Field Description

01 GPS lock 02 DGPS valid data 04 The ARM processor has

lock 08 DGPS solution 10 DGPS solution is good 20 Not used 40 Not used

An example of the NavCondition is presented in the following table for the 179889A value.

Field Description

A The number of satellites with lock and carrier phase 9 The number of satellites with ephemeris received 8 The number of satellites with healthy ephemeris 8 The number of satellites that are tracked, have an

ephemeris, which is healthy, and are above the elevation mask

9 The number of satellites above the elevation mask 7 The number of satellites with differential 1 The number of satellites with no differential


6.6.11 $PCSI,1 Beacon Status Message This message contains a variety of information relating to the status of a SI-TEX SBX engine inside the Vector PRO. The $PCSI,1 output message from the SBX beacon module is intelligently routed through the Vector PRO to the port from which the $PCSI,1 message was requested.

$PCSI,CS0,PXXX-Y.YYY,SN,fff.f,M,ddd,R,SS,SNR,MTP,Q,ID,H,T

Field Description

CS0 Channel 0 PXXX-Y.YYY

Resident SBX-3 firmware version

S/N SBX-3 receiver serial number fff.f Channel 0 current frequency M Frequency Mode (‘A’ - Auto or ‘M’ - Manual)

ddd MSK bit rate R RTCM rate

SS Signal strength SNR Signal to noise ratio MTP Message throughput Q Quality number {0-25} - number of successive good 30 bit RTCM words

received ID Beacon ID to which the receiver’s primary channel is tuned H Health of the tuned beacon [0-7] T $PCSI,1 status output period {0-99}


6.6.12 HDT Data Message This message provides true heading of the vessel. This is the direction that the vessel (Vector Antenna Array) is pointing and is not necessarily the direction of vessel motion (the course over ground). The HDT data message has the following format.

$HEHDT,x.x,T*cc<CR><LF>

Where ‘x.x’ is the current heading in degrees and ‘T’ indicates true heading.

6.6.13 ROT Data Message The ROT data message contains the vessel’s rate of turn information. It has the following format.

$HEROT,x.x,A*cc<CR><LF>

Where ‘x.x’ is the rate of turn in degrees per minute and ‘A’ is a flag indicating that the data is valid. The ‘x.x’ field is negative when the vessel bow turns to port.

6.6.14 HPR Data Message The $PSAT,HPR message is a proprietary NMEA sentence that provides the heading, pitch / roll information, and time in a single data message. This message has the following format.

$PSAT,HPR,time,heading,pitch,roll,*7B<CR><LF>

Field Description

time GPS time (HHMMSS.SS)

heading Heading (degrees) pitch Pitch (degrees) roll Roll (degrees)


6.7 Beacon Receiver Commands As mentioned above, we have implemented some command and message pass-through intelligence for communication to the internal SBX beacon module. In this configuration, the commands in the following table may be issued to the beacon receiver through either Port A or Port B of the Vector PRO.

Table 6-16 SBX Beacon Commands

Message Description

$GPMSK Command to turn on diagnostic information. $PCSI,1 This command is used to get beacon status information from the SBX

beacon engine inside the Vector PRO.

6.7.1 $GPMSK Beacon Tune Command This command instructs the SBX beacon engine to tune to a specified frequency and automatically select the correct MSK rate. When this command is sent through primary GPS Port A, it will automatically be routed to SBX. The resulting confirmation of this message will be returned to the same port from which the command was sent. It has the following form.

$GPMSK,fff.f,F,mmm,M,n<CR><LF

Response.

$PCSI,ACK,GPMSK,fff.f,F,mmm,M,n<CR><LF>


Field Description

fff.f This field is the beacon frequency in kHz (283.5 to 325) and may be left null if the receiver has not yet locked

F This field selects the frequency selection mode, either manual “M” or automatic “A”

mmm This field is the MSK bit rate. If the following field is set to automatic MSK rate “A”, this field can be left null

M Designates automatic MSK bit rate selection n Period of output of performance status message, 0 to 100 seconds ($CRMSS)

When this message is acknowledged by the SBX, it will immediately tune to the frequency specified and demodulate at the rate specified.

When the ‘n’ field is set to a non-zero value, the SBX will output the $CRMSS message at that period through the serial port from which the SBX was tuned. When issuing the tune command with a non-zero ‘n’ field through the secondary port, the periodic output of the $CRMSS message will not impact the output of RTCM on the main port. However, when tuning the SBX with a non-zero ‘n’ field through the primary port, the NMEA status message will be interspersed within the RTCM data. Most GPS engines will not be able to filter the NMEA message, causing the overall data to fail parity checking.

When power to the Vector PRO is removed and reapplied, the status output interval resets to zero (no output). Section 5.7.1.2 discusses the $CRMSS status message output by the SBX as initiated using this command.

Note - When tuning using the primary serial port, if the ‘n’ field in this message is non-zero, the status data message output by the SBX may interrupt the flow of RTCM data to the GPS receiver. Re-power the SBX to stop the output of the $CRMSS message, or re-tune the beacon receiver with the ‘n’ field set to zero.


6.7.2 $PCSI,1 Beacon Status Command This command is used to obtain $PCSI,CS0 beacon status data from the SBX beacon engine inside the Vector PRO. When this command is sent through either Port A or B, it will automatically be routed to Port C. The resulting $PCSI,CS0 message will be returned to the same port from which the command was sent at the desired rate. It has the following format.

$PCSI,1,x<CR><LF>

The beacon receiver will provide the following response.

$PCSI,ACK,1,x

Where x is the desired output period in seconds.

If you wish to have the CS0 message output for every power cycle, use the following derivative of this command.

$PCSI,1,x,S<CR><LF>

The beacon receiver will provide the following response.

$PCSI,ACK,1,x,S

Where x is the desired output period in seconds. The ‘S’ field must be present and be capitalized.

6.8 GPS Heading Commands This section details the various settings that relate to the GPS heading aspect of the Vector PRO system.

The following table summarizes the commands detailed in this section.


Table 6-17 GPS Heading Commands

Message Description

TILTAID Command to turn on tilt aiding and query the current feature status TILTCAL Command to calibrate tilt aiding and query the current feature status MAGAID Command to turn on magnetic aiding and query the current feature status MAGCAL Command to store a new magnetic calibration table MAGCLR Command to erase the current magnetic calibration and begin recording new

magnetic table data GYROAID Command to turn on gyro aiding and query the current feature status and query

the current feature status LEVEL Command to turn on level operation and query the current feature status CSEP Query to retrieve the current separation between GPS antennas MSEP Command to manually set the GPS antenna separation and query the current

setting HTAU Command to set the heading time constant and to query the current setting PTAU Command to set the pitch time constant and the query the current setting

HRTAU Command to set the rate of turn time constant and to query the current setting COGTAU Command to set the course over ground time constant and to query the current

setting SPDTAU Command to set the speed time constant and to query the current setting HBIAS Command to set the heading bias and to query the current setting PBIAS Command to set the pitch bias and to query the current setting

NEGTILT Command to turn on the negative tilt feature and to query the current setting ROLL Command to configure the Vector PRO for roll or pitch output

SEARCH Command to force a new RTK heading search SUMMARY Query to show the current conf iguration of the Vector PRO

HELP Query to show the available commands for GPS heading operation and status

6.8.1 $JATT,TILTAID The Vector PRO’s internal tilt sensor (accelerometer) is enabled by default and constrains the RTK heading solution to reduce startup and reacquisition times. Since this sensor resides inside the Vector PRO, the receiver enclosure must be installed in a horizontal plane, as must the Antenna Array,

To turn the tilt-aiding feature off, use the following command.


$JATT,TILTAID,NO<CR><LF>

You may turn this feature back on with the following command.

$JATT,TILTAID,YES,<CR><LF>


$JATT,TILTAID<CR><LF>

Note - If you choose to increase the antenna separation beyond the default 0.5 m length, use of tilt aiding is required.

6.8.2 $JATT,TILTCAL The tilt sensor of the Vector PRO can be calibrated in the field, however the Vector PRO enclosure must be horizontal when performing the calibration. To calibrate the Vector PRO’s internal tilt sensor, issue the following command.

$JATT,TILTCAL<CR><LF>

The calibration process takes about two seconds to complete. The calibration is automatically saved to memory for subsequent power cycles.

6.8.3 $JATT,MAGAID Use of the magnetic aiding feature is now required but for shipping purposes, this feature is disabled. In addition to reducing the time required to compute a heading solution, it can also provide a secondary source of heading when a GPS heading is not available. When you are ready to turn the magnetic aiding feature on, there are two different ways of calibrating. The magnetic sensor must be calibrated after the completion of the installation process.

To turn the magnetic-aiding feature on, use the following command.


$JATT,MAGAID,YES<CR><LF>

You may turn this feature back off with the following command.

$JATT,MAGAID,NO<CR><LF>


$JATT,MAGAID<CR><LF>

Note – Magnetic aiding is now always required.

6.8.4 $JATT,MAGCAL Metallic structures on the vessel affect a compass’ reading, so this effect must be ‘removed’ through the calibration process. Once the Vector PRO is installed in its final location, to use this feature, magnetic aiding must first be turned on, followed by its calibration. A valid GPS heading is mandatory for the calibration process. There are two different ways to calibrate the magnetometer.

The first way is to send a command to clear the current magnetic information to begin the initialization process. Then, if you leave the Vector powered continuously, it will automatically save the magnetic calibration tables when it is ready. This may take up to several days or even weeks depending on the dynamics of your vessel. There is no further calibration required. If you wish to check if the magnetic information has been saved, you can issue the following command.


The second method requires more work up front, but, ensures your magnetic calibration information is up to date and complete within a short period of time. A command to clear the current magnetic information must first be sent to begin the initialization process, followed by slowly rotating the vessel a full 360? approximately 3 to 10 times. Calibration should be performed in a clear environment without any potential satellite blockages to minimize any possible errors during the


process. The command to initialize the magnetic calibration process follows.


Once the command has been issued, the vessel needs to rotate 360? three to four times. The following command can be sent during the calibration procedure to ‘ask’ the Vector PRO if the calibration is complete and if so, to automatically save it to memory for subsequent power cycles.


If the Vector PRO enclosure is reinstalled in a different location, even on the same vessel, you will need to clear the calibration table with the $JATT,MAGCLR command and complete the new calibration. Similarly, if any objects containing metal are moved near or away from the sensor, this command will need to be sent to the receiver and a new calibration performed.

Note - It is very important to perform the calibration only after the installation of the Vector PRO has been confirmed to be complete. If the Vector PRO’s location is changed, you will need to clear the calibration and recalibrate. A valid GPS heading is required during the calibration process.

6.8.5 $JATT,MAGCLR This command is used to clear the magnetic calibration table inside the Vector PRO’s memory. It is issued in order to begin the process of calibrating the Vector PRO’s internal magnetic sensor. This command has the following format.


Once the command has been issued, you have two choices for calibration. You can either leave the Vector powered continuously and


the magnetic aiding feature will automatically save the settings after a period of time, or you can rotate the vessel 360? 3 to 10 times.

If you choose the second calibration option, the following command must be sent after the calibration procedure to ‘ask’ the Vector PRO if the calibration is complete and if so, to automatically save it to memory for subsequent power cycles.


If the receiver responds with a negative, continue rotating and re-issue the MAGCAL command periodically until the calibration has been accepted.

If the Vector PRO system is reinstalled in a different location, even on the same vessel, you will need to clear the calibration table with the $JATT,MAGCLR command and complete the new calibration.

Note - It is very important to perform the calibration only after the installation of the Vector PRO has been confirmed to be complete. If the Vector PRO’s location is changed, you will need to clear the calibration and recalibrate. A valid GPS heading is required during the calibration process.

6.8.6 $JATT,GYROAID The Vector’s internal gyro is shipped on by default, and it offers two benefits. It will shorten reacquisition times when a GPS heading is lost, due to obstruction of satellite signals, by reducing the search volume required for solution of the RTK. It will also provide an accurate substitute heading for a short period (depending on the roll and pitch of the vessel) ideally seeing the system through to reacquisition. This is why we highly recommend you leave the gyro aiding on.

Exceeding rates of 30 degrees per second is not recommended since the gyro cannot measure rates beyond this point. This is a new recommendation since we now use gyro measurements to get a heading rate measurement.


To turn on the gyro-aiding feature, use the following command.

$JATT,GYROAID,YES<CR><LF>

If you wish to turn this feature off, use the following command.

$JATT,GYROAID,NO<CR><LF>

If you wish to request the status of this message, send the following command.

$JATT,GYROAID<CR><LF>

The Vector’s gyro now requires a “warm-up” procedure. The gyro will automatically warm up by itself over time, but to ensure that it is ready when you need it, it is best to follow the procedure below.

When your Vector unit is installed, apply power and wait several minutes until it has acquired a GPS signal and it is computing heading. Ensure that the gyro-aiding feature is on by issuing a $JATT,GYROAID<CR><LF> command. Then, slowly spin the unit for one minute at a rate of no more than 15 degrees per second. Then, let it sit stationary for four minutes. Your Vector’s gyro is now fully calibrated. Since this setting cannot be saved, this procedure must be performed every time the Vector’s power is cycled.

6.8.7 $JATT,LEVEL This command is used to invoke the level operation mode of the Vector PRO. If your application will not involve the system tilting more than ?10? maximum, then you may choose to use this mode of operation. The benefit of using level operation is increased robustness and faster acquisition times of the RTK heading solution. By default, this feature is turned off. The command to turn this feature on follows.

$JATT,LEVEL,YES<CR><LF>

To turn this feature off, issue the following command.


$JATT,LEVEL,NO<CR><LF>

To determine the current status of this message, issue the following command.

$JATT,LEVEL<CR><LF>

6.8.8 $JATT,CSEP This command polls the Vector PRO for the current separation between antennas, as solved for by the attitude algorithms. It has the following format.

$JATT,CSEP<CR><LF>

The Vector PRO will reply with the following.

$JATT,x,CSEP,

Where ‘x‘ is the antenna separation in m.

6.8.9 $JATT,MSEP This command is used to manually enter a custom separation between antennas (must be accurate to within one to two centimeters). Using the new center-to-center measurement, send the following command to the Vector PRO.

$JATT,MSEP,sep<CR><LF>

Where ‘sep’ is the measured antenna separation entered in meters.

To show the current antenna separation, issue the following command.

$JATT,MSEP<CR><LF>


6.8.10 $JATT,HTAU The heading time constant allows you to adjust the level of responsiveness of the true heading measurement provided in the $HEHDT message. The default value of this constant is 0.5 seconds of smoothing. Increasing the time constant will increase the level of heading smoothing.


$JATT,HTAU,htau<CR><LF>

Where ‘htau’ is the new time constant that falls within the range of 0.0 to 3600.0 seconds.

Depending on the expected dynamics of the vessel, you may wish to adjust this parameter. For instance, if the vessel is very large and is not able to turn quickly, increasing this time is reasonable. The resulting heading would have reduced ‘noise’, resulting in consistent values with time. However, artificially increasing this value such that it does not agree with a more dynamic vessel could create a lag in the heading measurement with higher rates of turn. A convenient formula for determining what the level of smoothing follows. If you are unsure on how to set this value, it’s best to be conservative and leave it at the default setting.

htau (in seconds) = 10 /maximum rate of turn (in ?/s)


$JATT,HTAU<CR><LF>



6.8.11 $JATT,PTAU The pitch time constant allows you to adjust the level of responsiveness of the pitch measurement provided in the $PSAT,HPR message. The default value of this constant is 0.5 seconds of smoothing. Increasing the time constant will increase the level of pitch smoothing.

The following command is used to adjust the pitch time constant.

$JATT,PTAU,ptau<CR><LF>

Where ‘ptau’ is the new time constant that falls within the range of 0.0 to 3600.0 seconds.

Depending on the expected dynamics of the vessel, you may wish to adjust this parameter. For instance, if the vessel is very large and is not able to pitch quickly, increasing this time is reasonable. The resulting pitch would have reduced ‘noise’, resulting in consistent values with time. However, artificially increasing this value such that it does not agree with a more dynamic vessel could create a lag in the pitch measurement. A convenient formula for determining what the level of smoothing follows. If you are unsure on how to set this value, it’s best to be conservative and leave it at the default setting.

ptau (in seconds) = 10 / maximum rate of pitch (in ?/s)

You may query the Vector PRO for the current pitch time constant by issuing the same command without an argument.

$JATT,PTAU<CR><LF>



6.8.12 $JATT,HRTAU The heading rate time constant allows you to adjust the level of responsiveness of the rate of heading change measurement provided in the $HEROT message. The default value of this constant is 2.0 seconds of smoothing. Increasing the time constant will increase the level of heading smoothing.


$JATT,HRTAU,hrtau<CR><LF>

Where ‘hrtau’ is the new time constant that falls within the range of 0.0 to 3600.0 seconds.

Depending on the expected dynamics of the vessel, you may wish to adjust this parameter. For instance, if the vessel is very large and is not able to turn quickly, increasing this time is reasonable. The resulting heading would have reduced ‘noise’, resulting in consistent values with time. However, artificially increasing this value such that it does not agree with a more dynamic vessel could create a lag in the rate of heading change measurement with higher rates of turn. A convenient formula for determining what the level of smoothing follows. If you are unsure on how to set this value, it’s best to be conservative and leave it at the default setting.

hrtau (in seconds) = 10 / maximum rate of the rate of turn (in ?/s2)

You may query the Vector PRO for the current heading rate time constant by issuing the same command without an argument.

$JATT,HRTAU<CR><LF>



6.8.13 $JATT,COGTAU The course over ground (COG) time constant allows you to adjust the level of responsiveness of the COG measurement provided in the $GPVTG message. The default value of this constant is 0.0 seconds of smoothing. Increasing the time constant will increase the level of COG smoothing.

The following command is used to adjust the COG time constant.

$JATT,COGTAU,cogtau<CR><LF>

Where ‘cogtau’ is the new time constant that falls within the range of 0.0 to 3600.0 seconds.

As with the heading time constant, the setting of this value depends upon the expected dynamics of the vessel. If a boat is highly dynamic, this value should be set to a lower value since the filtering window needs be shorter in time, resulting in a more responsive measurement. However, if a vessel is very large and has much more resistance to change in its motion, this value can be increased to reduce measurement noise. The following formula provides some guidance on how to set this value. If you are unsure what is the best value for this setting, it’s best to be conservative and leave it at the default setting.

cogtau (in seconds) = 10 / maximum rate of change of course (in ?/s)


$JATT,COGTAU<CR><LF>



6.8.14 $JATT,SPDTAU The speed time constant allows you to adjust the level of responsiveness of the speed measurement provided in the $GPVTG message. The default value of this parameter is 0.0 seconds of smoothing. Increasing the time constant will increase the level of speed measurement smoothing.

The following command is used to adjust the speed time constant.

$JATT,SPDTAU,spdtau<CR><LF>

Where ‘spdtau’ is the new time constant that falls within the range of 0.0 to 3600.0 seconds.

As with the heading time constant, the setting of this value depends upon the expected dynamics of the vessel. If a boat is highly dynamic, this value should be set to a lower value since the filtering window would be shorter, resulting in a more responsive measurement. However, if a vessel is very large and has much more resistance to change in its motion, this value can be increased to reduce measurement noise. The following formula provides some guidance on how to set this value initially, however, we recommend that you test how the revised value works in practice. If you are unsure what is the best value for this setting, it’s best to be conservative and leave it at the default setting.

spdtau (in seconds) = 10 / maximum acceleration (in m/s2)


$JATT,SPDTAU<CR><LF>



6.8.15 $JATT,HBIAS You may adjust the heading output from the Vector PRO in order to calibrate the true heading of the Antenna Array to reflect the true heading of the vessel using the following command.

$JATT,HBIAS,x<CR><LF>

Where x is a bias that will be added to the Vector PRO’s heading, in degrees. The acceptable range for the heading bias is -180.0? to 180.0?. The default value of this feature is 0.0?.

To determine what the current heading compensation angle is, send the following message to the Vector PRO.

$JATT,HBIAS<CR><LF>

6.8.16 $JATT,PBIAS You may adjust the pitch / roll output from the Vector PRO in order to calibrate the measurement if the Antenna Array is not installed in a horizontal plane. The following NMEA message allows to you to calibrate the pitch / roll reading from the Vector PRO.

$JATT,PBIAS,x<CR><LF>

Where x is a bias that will be added to the Vector PRO’s pitch / roll measure, in degrees. The acceptable range for the heading bias is -15.0? to 15.0?. The default value of this feature is 0.0?.

To determine what the current pitch compensation angle is, send the following message to the Vector PRO.

$JATT,PBIAS<CR><LF>


Note - The pitch / roll bias is added after the negation of the pitch / roll measurement (if so invoked with the $JATT,NEGTILT command).

6.8.17 $JATT,NEGTILT When the secondary GPS antenna is below the primary GPS antenna, the angle from the horizon at the primary GPS antenna to the secondary GPS antenna is considered negative.

Depending on your convention for positive and negative pitch / roll, you may wish to change the sign (either positive or negative) of the pitch / roll. To do this, issue the following command.

$JATT,NEGTILT,YES<CR><LF>

To return the sign of the pitch / roll measurement to its original value, issue the following command.

$JATT,NEGTILT,NO<CR><LF>

To query the Vector PRO for the current state of this feature, issue the following command.

$JATT,NEGTILT<CR><LF>

6.8.18 $JATT,ROLL If you wish to get the roll measurement, you will need to install the Antenna Array perpendicular to the vessel’s axis, and send the following command to the Vector PRO.

$JATT,ROLL,YES<CR><LF>

If you wish to return the Vector PRO to its default mode of pricing the pitch measurement, issue the following command.

$JATT,ROLL,NO<CR><LF>


You may query the Vector PRO for the current roll / pitch status with the following command.

$JATT,ROLL<CR><LF>

6.8.19 $JATT,SEARCH You may force the Vector PRO to reject the current RTK heading solution, and have it begin a new search with the following command.

$JATT,SEARCH<CR><LF>

If the Vector PRO has a lock before this command is sent, you will see the heading LED go out once the command has been sent. The heading LED will turn back on when a new heading solution has been achieved.

6.8.20 $JATT,SUMMARY This command is used to receive a summary of the current Vector PRO settings. This command has the following format.

$JATT,SUMMARY<CR><LF>

The response has the following format.

$>JATT,SUMMARY,htau,hrtau,ptau,ctau,spdtau,hbias,pbias,hexflag<CR><LF>

An example of the response to this message follows.

$>JATT,SUMMARY,TAU:H=0.50,HR=2.00,P=0.50,COG=0.00,SPD=0.00,BIAS:H=0.00,P=0.00,FLAG_HEX:GN-RMTL=01


Field Description

htau This data field provides the current heading time constant in seconds hrtau This data field provides the current heading rate time constant in seconds ptau This data field provides the current pitch time constant in seconds

cogtau This data field provides the current course over ground time constant in seconds

spdtau This data field provides the current speed time constant in seconds hbias This data field gives the current heading bias in degrees pbias This data field gives the current pitch / roll bias in degrees

hexflag This field is a hex code that summarizes the heading feature status and is described in the following table

Value Flag

Feature On Feature Off

Gyro aiding 02 0 Negative tilt 01 0 Roll 08 0 Magnetic aiding

04 0

Tilt aiding 02 0 Level 01 0

The ‘GN-RMTL’ field is two separate hex flags, ‘GN’ and ‘RMTL’. The ‘GN’ value is determined by computing the sum of the gyro aiding and negative tilt values, depending if they are on or off. If the feature is on, their value is included in the sum. If the feature is off, it has a value of zero when computing the sum. The value of RMTL is computed in the same fashion but by adding the values of roll, magnetic aiding, tilt aiding, and level operation.

For example, if gyro aiding, roll, and magnetic aiding features were each on, the values of ‘GN’ and ‘RMTL’ would be the following:

GN = hex ( 02 + 0 ) = hex ( 02 ) = 2

RMTL = hex ( 08 + 04) = hex (12) = C


‘GN-RMTL’ = 2C

The following tables summarize the possible feature configurations for the first GN character and the second RMTL character.

GN Value Gyro Aiding Negative Tilt

0 Off Off 1 Off On 2 On Off 3 On On

RMTL Value Roll Mag Aiding Tilt Aiding Level

0 Off Off Off Off 1 Off Off Off On 2 Off Off On Off 3 Off Off On On 4 Off On Off Off 5 Off On Off On 6 Off On On Off 7 Off On On On 8 On Off Off Off 9 On Off Off On A On Off On Off B On Off On On C On On Off Off D On On Off On E On On On Off F On On On On

6.8.21 $JATT,HELP The Vector PRO supports a command that you can use to get a short list of the supported commands if you find yourself in the field without documentation.


This commands has the following format.

$JATT,HELP<CR><LF>

The response to this command will be the following.

$>JATT,HELP,CSEP,MSEP,EXACT,LEVEL,HTAU,HRTAU,HBIASPBIAS,NEGTILT,ROLL,TILTAID,TILTCAL,MAGAID,MAGCAL,MAGCLR,

GYROAID,COGTAU,SPDTAU,SEARCH,SUMMARY


7. Binary Data The Vector PRO supports a selection of binary data messages that provide improved communication port efficiency. Additionally, certain data is available only in binary format, such as raw measurement information.

Note - The binary messages described in this chapter are turned on or off using the $JBIN and $JOFF commands discussed in Chapter 6.

7.1 Binary Message Structure The Binary messages supported by the Vector PRO are in an Intel Little Endian format for direct read in a PC environment. You can find more information on this format at the following Web site.

www.cs.umass.edu/~verts/cs32/endian.html

Each binary message begins with an 8-byte header and ends with a carriage-return line-feed pair (0x0D, 0x0A). The first four characters of the header is the ASCII sequence $BIN.

The following table provides the general binary message structure.

Note - For clarity, each table begins on a new page.


Table 7-1 Binary Message Structure

Group Components Type Bytes Value

Synchronization String 4 byte string

4 $BIN

BlockID - a number which tells the type of binary message

Unsigned short

2 1, 2, 80, 93, 94, 95, 96, 97, 98, or 99

Header

DataLength - the length of the binary messages

Unsigned short

2 52, 16, 40, 56, 96, 128, 300, 28, 68, or 304

Data Binary Data - varying fields of data with a total length of DataLength bytes

Mixed fields 52, 16, 40, 56, 96, 128, 300, 28, 68, or 304

Varies - see message tables

Checksum - sum of all bytes of the data (all DataLength bytes). The sum is placed in a 2-byte integer

Unsigned short

2 Sum of data bytes

CR - Carriage return Byte 1 0D hex

Epilogue

LF - Line feed Byte 1 0A hex The total length of the binary message packet is DataLength plus 12 (8 byte header, 2 byte checksum, and 2 bytes for CR, LF).


7.1.1 Bin 1 This message has a BlockID of 1 and is 52 bytes excluding the header and epilogue. It consists of GPS position and velocity data. It is the only binary message that can be output at a rate of 5 Hz. The following table describes the content of this message.

Table 7-2 Bin 1 Message

Name Components Type Bytes

Value

AgeOfDiff Age of differential, seconds. Use Extended AgeOfDiff first. If both = 0 then no differential

Byte 1 0 to 255

NumOfSats Number of satellites used in the GPS solution

Byte 1 0 to 12

GPSWeek GPS week associated with this message

Unsigned short

2 0 to 65536

GPSTimeOfWeek GPS tow (sec) associated with this message

Double 8 0.0 to 604800.0

Latitude Latitude in degrees North Double 8 -90.0 to 90.0 Longitude Longitude in degrees East Double 8 -180.0 to 180.0 Height Altitude above the ellipsoid

in meters Float 4

VNorth Velocity north in m/s Float 4 VEast Velocity East in n/s Float 4 VUp Velocity up in m/s Float 4 Positive NavMode Navigation mode:

0 = No fix 1 = 2D no diff 2 = 3D no diff 3 = 2D with diff 4, 5, or 6 = 3D with diff If bit 7 is set (left-most bit), then this is a manual mark position

Unsigned short

2 Bits 0 through 6 = Navmode Bit 7 = Manual mark

Extended AgeOfDiff

Extended age of differential, seconds. If 0, use 1 byte AgeOfDiff listed above

Unsigned short

2 0 to 65536


7.1.2 Bin 2 This message has a BlockID of 2 and is 16 bytes excluding the header and epilogue. This message contains various quantities that are related to the GPS solution. The following table describes the details of this message in order.


Name Components Type Bytes Value

MaskSatsTracked

A mask of satellites tracked by the GPS. Bit 0 corresponds to the GPS satellite with PRN 1.

Unsigned long

4 Individual bits represent satellites

MaskSatsUsed A mask of satellites used in the GPS solution. Bit 0 corresponds to the GPS satellite with PRN 1.

Unsigned long

4 Individual bits represent satellites

GPSUtcDiff Whole seconds between UTC and GPS time (GPS minus UTC)

Unsigned short

2 Positive

HDOPTimes10 Horizontal dilution of precision scaled by 10 (0.1 units)

Unsigned short

2 Positive

VDOPTimes10 Vertical Dilution of precision scaled by 10 (0.1 units)

Unsigned short

2 Positive

WAAS PRN bitmask

PRN and tracked or used status masks

Unsigned short

2 See below

WAAS PRN bit mask.

• Bit 00 Mask of satellites tracked by first WAAS satellite • Bit 01 Mask of satellites tracked by second WAAS satellite • Bit 02 Mask of satellites used by first WAAS satellite • Bit 03 Mask of satellites used by second WAAS satellite • Bit 04 Unused • Bit 05-09 Value used to find PRN of first WAAS satellite (This value + 120 = PRN) • Bit 10-14 Value used to find PRN of second WAAS satellite (This value + 120 = PRN)


• Bit 15 Unused

7.1.3 Bin 80 This message has a BlockID of 80 and is 40 bytes excluding the header and epilogue. This message contains the WAAS message. The following table describes the constituents of this message in order.



PRN Broadcast PRN Unsigned short

2

Spare Not used at this time Unsigned short

2 Future use

MsgSecOfWeek

Seconds of week for message

Unsigned long 4

WaasMsg[8] 250 bit WAAS message (RTCA DO-229). 8 unsigned longs with most significant bit received first

Unsigned long 4 x 8 = 32


7.1.4 Bin 93 This message has a BlockID of 93 and is 45 bytes excluding the header and epilogue. This message contains information relating to the WAAS ephemeris. The following table describes the contents of this message in order



SV Satellite to which this data belongs

Unsigned short

2


2 Future use

TOWSecOfWeek Time at which this arrived (LSB = 1 sec)

Unsigned long 4

IODE Unsigned short

2

URA Consult the ICD-GPS-200 for definition in Appendix C - Resources

Unsigned short

2

T0 Bit 0 = 1 sec Long 4 XG Bit 0 = 0.08 m Long 4 YG Bit 0 = 0.08 m Long 4 ZG Bit 0 = 0.4 m Long 4 XGDot Bit 0 = 0.000625 m/s Long 4 YXDot Bit 0 = 0.000625 m/s Long 4 ZGDot Bit 0 = 0.004 m/s Long 4 XGDotDot Bit 0 = 0.0000125 m/s2 Long 4 YGDotDot Bit 0 = 0.0000125 m/s2 Long 4 ZGDotDot Bit 0 = 0.0000625 m/s2 Long 4 Gf0 Bit 0 = 2**-31 s Unsigned

short 2

Gf0Dot Bit0 = 2**-40 s/s Unsigned short

2


7.1.5 Bin 94 This message has a BlockID of 94 and is 96 bytes excluding the header and epilogue. This message contains ionospheric and UTC conversion parameters. The following table describes the details of this message in order.



a0,a1, a2,a3

AFCRL alpha parameters Double 8 x 4 = 32

b0,b1,b2,b3

AFCRL beta parameters Double 8 x 4 = 32

A0,A1 Coefficients for determining UTC time

Double 8 x 2 = 16

tot Reference time for A0 and A1, second of GPS week

Unsigned long

4

wnt Current UTC reference week Unsigned short

2

wnlsf Week number when dtlsf becomes effective

Unsigned short

2

dn Day of week (1-7) when dtlsf becomes effective

Unsigned short

2

dtls Cumulative past leap Short 2 dtlsf Scheduled future leap Short 2 Spare Not used at this time Unsigned

short 2 Future

use


7.1.6 Bin 95 This message has a BlockID of 95 and is 128 bits excluding the header and epilogue. This message contains ephemeris data of all 12 channels. The following table describes the contents of this message in order.



SV The satellite to which this data belongs

Unsigned short

2

Spare1 Not used at this time Unsigned short

2 Future use

SecOfWeek Time at which this arrived (LSB = 6)

Unsigned long

4

SF1words[10]

Unparsed SF 1 message Unsigned long

4 x 10 = 40

SF2words[10]


4 x 10 = 40

SF3words[10]


4 x 10 = 40


7.1.7 Bin 96 This message has a BlockID of 96 and is 300 bytes excluding the header and epilogue. This message contains phase and code data. The following table describes the constituents of this message in order.



Spare1 Not used at this time Unsigned short

2 Future use

Week GPS week number Unsigned short

2

TOW Predicted GPS time in seconds

Double 8

UICS_TT_SNR_PRN[12] See below Unsigned long 4 x 12 = 48 UIDoppler_FL[12] See below Unsigned long 4 x 12 = 48 PseudoRange[12] Pseudoranges Double 8 x 12 = 96 Phase[12] Phase (m) L1 wave =

0.190293672798365 m

Double 8 x 12 = 96

Where.

UlCS_TT_SNR_PRN

• Bits 0-7: PRN (PRN is 0 if no data) • Bits 8-15: SNR value (SNR= 10.0 * log10 * (0.8192 * SNR value)) • Bits 16-23: Phase Track Time in units of 1/10 second, range = 0 to 25.5 seconds (see next word) • Bits 24-31: Cycle Slip Counter (Increments by 1 every cycle slip with natural rollover after 255)

UlDoppler_FL

• Bit 0: 1 if Valid Phase, 0 otherwise • Bit 1: 1 if Track Time > 25.5 seconds, 0 otherwise • Bits 2-3: Unused • Bits 4-31: Signed (two’s compliment) Doppler in units of m/sec x 4096. (i.e., LSB=1/4096), range = +/- 32768 m/sec. Computed as phase change over 1/10 sec.


7.1.8 Bin 97 This message has a BlockID of 97 and is 28 bytes excluding the header and epilogue. This message contains statistics for processor utilization. The following table describes the details of this message in order.



CPUFactor CPU utilization factor. Multiply by 450e-06 to get percentage of spare CPU that is available

Unsigned long 4 Positive

MissedSubFrame The total number of missed sub frames in the navigation message since power on

Unsigned short

2 Positive

MaxSubFramePnd Max sub frames queued Unsigned short

2 Positive

MissedAccum The total number of missed code accumulation measurements in the channel-tracking loop

Unsigned short

2 Positive

MissedMeas The total number of missed psuedorange measurements

Unsigned short

2 Positive

Spare 1 Not used at this time Unsigned long 4 Future use



Spare 4 Not used at this time Unsigned short

2 Future use

Spare 5 Not used at this time Unsigned short

2 Future use


7.1.9 Bin 98 This message has a BlockID of 98 and is 68 bytes excluding the header and epilogue. This message contains data derived from the satellite almanacs. The following table describes the contents of this message in order.



AlmanData Almanac-derived-data, 8 satellites at a time

Structure array

8 x 8 = 64 See the following table

LastAlman Last almanac processed Byte 1 0 to 31 IonoUTCVFlag Flag that is set when

ionosphere modeling data is extracted from the GPS sub frame 4

Byte 1 0 = not logged 2 = valid


2 Future use

AlmanData Structure Array


DoppHz Predicted Doppler in Hz for the satellite in question (assuming a stationary satellite).

Short 2

CountUpdate Number of times the almanac has changed for this satellite since the receiver was turned on

Byte 1 Positive

Svindex Channel number (groups of 8) Byte 1 0 to 7 8 to 15 16 to 23 24 to 31

AlmVFlag Almanac valid flag Byte 1 0 = not logged 1 = invalid 2 = valid 3 = has data


(not yet validated)

AlmHealth Almanac health from sub frame 4 of the GPS message

Byte 1 See ICD-GPS-200

Elev Elevation angle in degrees Char 1 -90 to 90 Azimuth ½ the azimuth in degrees Byte 1 0 to 180

represents 360 degrees


7.1.10 Bin 99 This message has a BlockID of 99 and is 304 bytes excluding the header and epilogue. This message contains quantities related to the tracking of the individual GPS satellites along with some other relevant data. The following table describes the constituents of this message in order.



NavMode2 Navigation mode data (lower 3 bits hold the GPS mode, upper bit set if differential is available).

Byte 1 Lower 3 bits: 0 = time not valid 1 = no fix 2 = 2D fix 3 = 3D fix Upper bit (bit 7) is 1 if differential is available

UTCTimeDiff Whole seconds between UTC and GPS time (GPS minus UTC)

Byte 1 Positive

GPSWeek GPS week associated with this message

Unsigned short

2 0 to 65536

GPSTimeOfWeek GPS tow (sec) associated with this message

Double 8 0.0 to 604800.0

ChannelData 12 structures (see below) containing tracking data for each of the 12 receiver channels

Structure array

12 x 24 = 288

See following table

ClockErrAtL1 The clock error of the GPS clock oscillator at L1 frequency in Hz

Short 2 -32768 to 32768


2 Future use


ChannelData Array


Channel Channel number Byte 1 0 to 12 SV Satellite being tracked, 0 == not

tracked Byte 1 0 to 32

Status Status bit mask (code carrier bit frame)

Byte 1 Bit 0 = code lock 1 = carrier lock 2 = bit lock 3 = frame sync 4 = frame sync and new epoch 5 = channel reset 6 = phase lock 7 = spare

LastSubFrame

Last sub frame processed in the GPS message

Byte 1 1 to 5

EphmVFlag Ephemeris valid flag Byte 1 0 = not logged 1 = invalid 2 = valid 3 = has data (not yet validated)

EphmHealth Satellite health from sub frame 1 of the GPS message


AlmVFlag Almanac valid flag Byte 1 0 = not logged 1 = invalid 2 = valid 3 = has data (not yet validated)

AlmHealth Almanac health from sub frame 4 of the GPS message


Elev Elevation angle in degrees Char 1 -90 to 90 Azimuth ½ the azimuth in degrees Byte 1 0 to 180 degrees

represents 0 to 360 degrees

URA User range error from sub frame 1 of the GPS message


Spare Not used at this time Byte 1 Future use CliForSNR Code lock indicator for SNR. SNR

= 10.0 * 4096 CliForSNR / Nose_floor) where Nise_floor = 80000.0

Unsigned short

2 Positive


DiffCorr 100 times the differential correction for this channel’s psuedorange

Short 2

PosResid 10 times the position residual from the GPS solution for this chanel

Short 2

VelResid 10 times the velocity residual from the GPS solution for this channel

Short 2

DoppHZ Expected Doppler for this channel in Hz

Short 2

NCOHz Carrier track offset for this channel in Hz

Short 2


8. Frequently Asked Questions

8.1 Heading Q - How shall I mount the Vector PRO?

A - It depends on whether or not you want to pole-mount or fix-mount the system. Offering both options provides some flexibility when mounting the Vector. If you choose to pole-mount, ensure that you use the washer and lock nut supplied.

Q - Should I turn on all the supplemental sensors?

A – We highly recommend as that you leave the tilt sensor turned on and that you turn on the gyro and the magnetic sensor. The magnetic sensor requires calibration, but it greatly helps the heading performance, especially during GPS outages.

8.2 General Q - Do you recommend beacon or SBAS differential services?

A - It partially depends on regulations regarding on the size of your vessel and if you’re going to use the Vector PRO for positioning in addition to heading. You may be required to use beacon corrections when positioning if you plan to use the position output from the Vector PRO. If this is not the case, you will likely find that the beacon and SBAS are able to provide good levels of performance. However, currently, the SBAS services are not currently transmitting under an initial operational capability declaration. Some degree of caution should be used when positioning with SBAS until these services achieve this level of compliance.


Q - Are the SBAS services reliable for differential operation?

A - These services have proven themselves for some time now and have shown excellent results. As both WAAS and EGNOS are in test mode currently, they are not to be used as a sole means of navigation. Additionally, as they are under test, there may be periods of outage or times when the signal should not be used. We recommend that you refer to Appendix C - Resources of this manual for Web sites that provide details regarding the broadcast schedule of WAAS and EGNOS.

Q - Can the COAST technology work with corrections from an external source?

A - Yes, the Vector PRO will operate in a similar fashion with the COAST technology as when using SBAS or beacon corrections. However, SBAS corrections have the advantage that they are separated into separate error components, allowing the Vector PRO to anticipate how errors will change over the coasting period with more consistent accuracy and for a longer period than regular RTCM range corrections.

8.3 Support and Repairs Q - How do you recommend that I pursue support to solve a problem that I can’t isolate?

A - We recommend that you contact your dealer first. With their experience with this and other products, they’re likely to help you isolate a problem. If the issue is beyond the capability or experience of your dealer, either they or you can speak with a Technical Service Representative from CSI Wireless.

Q - Can I contact CSI Wireless directly regarding technical problems?

A - Yes, however, we recommend that you speak to your dealer first as they would be your local support. They may be able to solve your problem more promptly than us, due to their location and experience with our equipment.


8.4 Troubleshooting Q - What do I do initially if I have a problem with the operation of the Vector PRO?

A - Try to isolate the source of the problem. Problems are likely to fall within one of the following categories. It’s important to review each in detail to remove each from being a suspect source of the problem.

• Power, communication, and configuration • GPS reception and performance • Beacon reception and performance • SBAS reception and performance • External corrections • Installation

The questions in the following sections provide information that may help you to isolate and solve the problem that you are experiencing.

Q - What do I do if I can’t resolve the problem after trying to diagnose it myself?

A - You should contact your dealer to see if they have any information that may help to solve the problem. They may be able to provide some in-person assistance too. If this either isn’t viable or does not solve the problem, CSI Wireless Technical Support is available during normal business hours to help solve the problem. You may reach Technical Support at:

Telephone number: +1-403-259-3311 Fax number: +1-403-259-8866 E-mail address: [email protected]

Technical Support is available from 8:00 AM to 5:00 PM Mountain Time, Monday to Friday.


8.5 Power, Communication, and Configuration Q - My Vector PRO doesn’t appear to be communicating, what do I do?

A - This could be one of a few issues:

1. Examine the power / data cable and its connector for signs of damage. The Vector PRO may be powered incorrectly, or the conductor carrying power to the antenna may be damaged (open).

2. Ensure that you are properly powering the system with the correct voltage by measuring the voltage at the receiver end of the power cable when the cable is connected to the power source.

3. Since you’re required to terminate the power / data input, ensure that you have made a good connection to the power supply and that the data interface is wired correctly.

4. Ensure that you’re communicating at the correct baud rate

5. Consult the troubleshooting section of the other devices reference manual to determine if there may be a problem with that equipment.

Q - Am I able to configure the two serial ports with different baud rates?

A - Yes, the ports are independent. For instance, you may have one port set to 4800 and the other to 19,200, or vice versa.

Q - Am I able to have the Vector PRO output different NMEA messages through the two ports?

A - Yes, you may have different NMEA messages turned on for the two serial ports. Further, these NMEA messages may also be at different update rates.


Q - How can I determine what the current configuration of the Vector PRO is?

A - The $JSHOW<CR><LF> command will request the configuration information from the Vector PRO’s internal GPS engine. The response will be similar to the following output and is described in detail in Chapter 6.

$>JSHOW,BAUD,19200 $>JSHOW,BIN,1,5.0 $>JSHOW,BAUD,4800,OTHER $>JSHOW,ASC,GPGGA,1.0,OTHER $>JSHOW,ASC,GPVTG,1.0,OTHER $>JSHOW,ASC,GPGSA,1.0,OTHER $>JSHOW,ASC,GPZDA,1.0,OTHER

You should also query each heading feature of the Vector PRO to determine their settings, such as the magnetic and tilt aiding using their associated commands.

Q - How can I be sure that the configuration will be saved for the subsequent power cycle?

A - The surest method is to query the receiver to make sure you’re happy with the current configuration, by issuing a $JSHOW<CR><LF> command (if not make the necessary changes and repeat). If the current configuration is acceptable, issue a $JSAVE<CR><LF> command. Wait for the receiver to indicate that the save is complete. You may power the receiver down and issue another $JSAVE if you feel it’s necessary, however, it is not required.

Q - What is the best software tool to use to communicate with the Vector PRO and configure it?

A - We use two different software applications at SI-TEX for this application, however you may have other preferences.

• PocketMAX - Available from the CSI Wireless Web site. This application is a very useful tool for graphically viewing tracking performance, positioning accuracy, and more.


• HyperTerminal - Available on all Windows 95, 98, and ME. This tool is useful as it allows you to easily configure the Vector PRO by directly typing commands into the terminal window. The output from the Vector PRO is shown simultaneously. Ensure that when using HyperTerminal that it is configured to use the correct PC communication port, baud rate, and that the local echo feature is on (to see what you are typing).

8.6 GPS Reception and Performance Q - How do I know what the GPS inside the Vector PRO is doing?

A - The GPS engine supports standard NMEA data messages. The $GPGSV data message contains satellite tracking information. Since the GPS automatically tracks GPS satellites when powered, this will give you information on the tracking status. If your receiver has computed a position, this will be contained within the $GPGGA data message. Also, the front panel LEDs provide status indication.

Q - Do I have to be careful when using the Vector PRO to ensure that it tracks properly?

A - For best performance, you have to be careful such that the hemisphere above the Vector Antenna Array is unobstructed for satellite tracking. The Vector PRO is tolerable of a certain amount of signal blockage due to the availability of redundant satellites. However, as more satellites are blocked, the more impact this could have your positioning accuracy. Tracking a lower number of satellites has the potential to reduce positioning performance. If a satellite is blocked due to an obstruction, it’s also possible that the obstruction is contributing multipath into the position solution, which will also degrade performance.

8.7 SBAS Reception and Performance Q - How do I know if I can receive a SBAS signal in my area?

A - Refer to Appendix B that contains approximate coverage maps for both WAAS (for North America) and EGNOS (for Europe). It’s important


to have both signal coverage and ionospheric map coverage. In fact, it’s desirable to have a few degrees of latitude and longitude of ionospheric map coverage around your location to ensure that satellites available have these correctors.

Q - How do I know if the Vector PRO antenna has acquired a SBAS signal?

A - The Vector PRO allows you to request the output of the $RD1 message that contains the SBAS bit error rate (BER) for both receiver channels. The BER value describes the rate of errors received from SBAS. Ideally, this should be zero, however, the Vector PRO should provide good performance up to a 150 BER. The PocketMAX utility discussed in Chapter 5 is a useful tool that provides this information without needing to use NMEA commands.

Q - How do I know if the Vector PRO is offering a differentially corrected position?

A - The Vector PRO outputs the GGA message as the main positioning data message by default. This message contains a quality fix value that describes the GPS status. If this value is a 2, then the position is differentially corrected. The PocketMAX utility discussed in Chapter 5 is a useful tool that provides this information without needing to use NMEA commands.

Q - Does it matter much if the Vector PRO is frequently losing lock on SBAS due obstructions and the low satellite elevation angles at my geographic location?

A - No, provided that the receiver is receiving a full set of corrections relatively often. Using the COAST technology, the Vector PRO will be able to perform well for up to 30 to 40 minutes with old correction data, depending on the degree of tolerable drift. In order to obtain a full set of corrections, the Vector PRO receives the ionospheric map over a period of a few minutes. This is the minimum amount of time required to get a full set of corrections for SBAS operation. After this, the receiver can coast until the next set of corrections has been received.


8.8 Beacon Reception and Performance Q - How do I know if I can receive a beacon signal in my area?

A - Refer to Appendix B that contains approximate coverage maps for both beacon networks. To ensure you have the most up to date information, please contact your local Coast Guard authority who manages the service for the network details.

Q - How do I know if the Vector PRO antenna has acquired a beacon signal?

A - You can receive the signal strength (SS) and signal to noise ratio (SNR) from the internal beacon sensor by sending a request for the CS0 message with the $PCSI,1<CR><LF> command. This information will tell you the quality of a lock.

Q - How do I know if the Vector PRO is offering a differentially corrected position?

A - The Vector PRO outputs the GGA message as the main positioning data message by default. This message contains a quality fix value that describes the GPS status. If this value is a 2, then the position is differentially corrected. The PocketMAX utility discussed in Chapter 5 is a useful tool that provides this information without needing to use NMEA commands.

Q - Does it matter much if the Vector PRO is frequently losing lock on beacon signals due to a noisy environment or weak signals?

A - No, provided that the receiver is receiving a full set of corrections relatively often. Using the COAST technology, the Vector PRO will be able to perform well for up to 30 to 40 minutes with old correction data, depending on the degree of tolerable drift. In order to obtain a full set of corrections, the beacon receiver needs to be locked for a few seconds for a 200 bps station, depending on the number of satellite corrections be transmitted. For a 100 bps modulation rate, it could take up to six or more seconds, depending on the number of satellite corrections being


sent. After this, the receiver can coast until the next set of corrections has been received, if there’s further data loss.

8.9 External Corrections Q - My Vector PRO doesn’t appear to be using corrections from an external correction source, what could be the problem?

A - This could be due to a number of issues:

• Make sure that the corrections are of an RTCM SC-104 protocol. • Check to see that the baud rates of the port used by the Vector PRO matches that of the external correction source • The external correction source should be using an 8 data bit, no parity, and 1 stop bit serial port configuration. • Inspect the cable connection to ensure there’s no sign of damage • Check the pin-out information for the cables to ensure that the transmit line of the external correction source is connected to the receive line of the Vector PRO’s serial port and that the signal grounds are connected.

8.10 Installation Q - Does it matter where I mount the Vector PRO?

A - Yes, as the main consideration is that it must have an open hemisphere of sky for satellite tracking. Additionally, the position that it computes is reference to the center of the primary GPS antenna. It should be placed in the location for which you would like a position. Often, this is the center line of a vessel.

Q - I have a vessel with a large amount of metal on it, including masts, outriggers, etc. How will this affect performance of the Vector PRO?

A - To some extent, it depends on where you have the Vector PRO mounted. Ideally, you will want as much of the metallic objects well below the horizon of the antenna. The antennas inside the Vector PRO are still sensitive to a degree, to signals reflected from below, but


ensuring that the reflective surfaces are below the antenna maximizes the possible performance.

The metallic surfaces reflect a delayed signal to the antenna, which can cause cycle slips in the RTK solution for satellites being track, and can reduce the integrity of the heading system. These multipath signals should be given considerable regard when considering a location to mount the Vector PRO.


9. Troubleshooting Use the following checklist to troubleshoot anomalous Vector PRO receiver operation. Table 9-1 provides a problem symptom, followed by a list of possible solutions.

Table 9-1 Troubleshooting

Symptom Possible Solution

Receiver fails to pow er • Verify polarity of power leads • Check integrity of power cable

connections • Check power input voltage (8 to 40 VDC) • Check current restrictions imposed by

power source (minimum available should be > 1.0 A)

No data from Vector PRO • Check receiver power status to ensure that the receiver is powered (you can use an ammeter for this)

• Verify that Vector PRO is locked to a valid DGPS signal (this can often be done on the receiving device or with the use with PocketMAX running on a PC)

• Verify that Vector PRO is locked to GPS satellites (this can often be done on the receiving device or with the use with PocketMAX running on a PC)

• Check integrity and connectivity of power and data cable connections

Random data from Vector PRO

• Verify that the RTCM or binary messages are not being output accidentally (send a $JSHOW command)

• Verify baud rate settings of Vector PRO and remote device match correctly

• Potentially, the volume of data requested to be output by the Vector PRO could be higher than the current baud rate supports. Try using 19,200 as the baud rate for all devices or reduce the amount of data being output

No GPS lock • Check integrity of antenna cable


• Verify Vector Antenna Array’s unobstructed view of the sky

• Verify the lock status of GPS satellites (this can often be done on the receiving device or with the use with PocketMAX running on a PC)

No SBAS lock • Check antenna connections • Verify Vector Antenna Array’s

unobstructed view of the sky • Verify the lock status of SBAS satellites

(this can often be done on the receiving device or with the use with PocketMAX running on a PC - monitor BER value)

No beacon lock • Verify that the receiver is tuned to the correct frequency and bit rate

• Ensure that beacon signal coverage is expected in your area

• Make sure that environmental noise is not masking the signal, reducing the SNR reading

No DGPS position in external RTCM mode

• Verify that the baud rate of the RTCM input port matches the baud rate of the external source

• Verify the pin-out between the RTCM source and the RTCM input port (transmit from the source must go to receive of the RTCM input port and grounds must be connected

Non-differential GPS output • Verify Vector PRO SBAS and beacon lock status (or external source is locked)

• Confirm baud rates match an external source correctly

• Issue a $JDIFF<CR><LF> command and see if the expected differential mode is in fact the current mode


Appendix A - Specifications This appendix provides the operational, mechanical, electrical, physical, and environmental specifications of the Vector PRO system.

Table A-1 Vector PRO Specifications

Internal GPS Engine Operational Specifications Item Specification

Frequency 1.575 GHz Channels 12 parallel tracking Horizontal Accuracy < 1 m 95% Maximum Position Update Rate 5 Hz Maximum Heading Update Rate 10 Hz

Internal Beacon Engine Operational Specifications

Item Specification

Frequency 283.5 to 325.0 kHz Receiver Channels 2 Frequency Channels 84 MSK Bit Rates 100, 200, or automatic Input Sensitivity 2.4 ?V for 6 dB SNR @ 200 bps Frequency Selection Manual or automatic Frequency offset + 5 Hz Dynamic Range 100 dB Adjacent Channel Rejection 61 dB + 1 @ fo +400 Hz Demodulation Minimum shift keying (MSK) Decoding RTCM SC-104 6/8


Serial Interface Specifications (standard cable) Item Specification

Serial Port Interface Level RS-232C and RS-422 RS-232 Serial Ports Primary receiver, one full duplex and one half

duplex (output). Secondary receiver one full duplex

RS-422 Serial Ports Two half-duplex (outputs) from primary GPS receiver

Available Baud Rates 4800, 9600, 19200, and 38,400 Baud Output Protocol NMEA 0183, binary Input Protocol NMEA 0183 External Correction Input Protocol

RTCM SC-104

Power Specifications

Item Specification

Input Voltage 8 to 40 VDC Power Consumption < 6 W Nominal

Mechanical Characteristics

Item Specification

Enclosure Extruded aluminum with cast aluminum front and end plates

Antenna Connectors TNC socket Length 203 mm (8.00”) Width 139 mm (5.47”) Height 64 mm (2.52”) Weight < 1000 g (< 2.2 lb) - no cables

Environmental Specifications

Item Specification

Storage Temperature -40 o C to 85? C Operating Temperature -30? C to 70o

C Humidity 100% condensing


Appendix B - Introduction to GPS, SBAS, and Beacon This chapter provides a brief overview of GPS, differential GPS, Space Based Augmentation Systems (SBAS) such as WAAS / EGNOS / MSAS, and beacon differential services.

GPS The United States Department of Defense (DoD) operates a reliable, 24 hour a day, all weather Global Positioning System (GPS).

Navstar, the original name given to this geographic positioning and navigation tool, includes a constellation of 24 satellites (plus active spares) orbiting the Earth at an altitude of approximately 22,000 km.

How it Works

These satellites transmit coded information to GPS users at UHF (1.575 GHz) frequencies that allows user equipment to calculate a range to each satellite. GPS is essentially a timing system - ranges are calculated by timing how long it takes for the coded GPS signal to reach the user’s GPS antenna.

To calculate a geographic position, the GPS receiver uses a complex algorithm incorporating satellite coordinates and ranges to each satellite. Reception of any four or more of these signals allows a GPS receiver to compute 3D coordinates. Tracking of only three satellites reduces the position fix to 2D coordinates (horizontal with fixed vertical).

The GPS receiver calculates its position with respect to the phase center of the GPS antenna. The latitude, longitude, and altitude of the antenna are referenced according to the World Geodetic System 1984 ellipsoid (WGS-84).


GPS Services

The positioning accuracy offered by GPS varies depending upon the type of service and equipment available. For security reasons, two GPS services exist: the Standard Positioning Service (SPS) and the Precise Positioning Service (PPS). The SPS uses a code modulated onto the signal for measurements and is referred to as the Coarse Acquisition code (C/A code). The US Department of Defense (DoD) reserves the PPS for use by its personnel and authorized partners. The PPS uses a different code than the SPS, referred to as the Precise Code (P-code) and contains more resolution than the C/A code. The DoD provides the SPS free of charge, worldwide, to all civilian users.

In order to maintain a strategic advantage, the US DoD used to artificially degrade the performance of the SPS so that the positioning accuracy was limited to 100 meters 95% of the time. This intentional degradation is called Selective Availability (SA). The effect of SA has been turned to zero since mid-2000, however, it has not been officially ‘turned off’.

Currently, autonomous GPS is able to provide accuracy on the order of 10 meters, depending on the sophistication of the GPS engine. For many positioning and navigation applications, this level of accuracy is not sufficient, and differential techniques must be employed.

Differential GPS The primary sources of errors that degrade GPS performance include SA (currently set to a zero effect), atmospheric errors, timing errors, satellite orbit errors, and multipath. Differential GPS (DGPS) is essentially a differencing process that removes sources of error from the GPS position solution and improves the integrity of the GPS position solution.

There are a number of methods of differential measurement correction.


• Conventional real-time differential - This is the most common form of correcting GPS errors in real-time with corrections sent to the rover GPS receiver by some form of communications equipment. Conventional real-time differential uses C/A code range measurements and their associated corrections. Carrier phase corrections are not used with this form of differential technique. • Post processing - This method is often used when either higher accuracy than achievable through conventional differential is needed, or a conventional form of real-time corrections is not available in the region where the rover receiver is being operated. Depending on receiver hardware and the methodology used for post process, performance can be from many centimeters to millimeter precision. A variety of 3rd party software packages are available to post process GPS raw measurement data. The Vector PRO can be configured to output raw measurement data at rates of up to 5 Hz in a proprietary format. This data can be converted to an industry standard RINEX format if needed. • Real-Time Kinematic - This method uses more sophisticated techniques to resolve the number of wavelengths between the satellite and the user, to provide centimeter-level positioning (or better) in real-time. This technique uses high-end receiver hardware, antennas, and internal operating software to compute accurate position solutions. The compromise with this method of differential correction is increased system complexity, cost, and operating constraints.

The Vector PRO includes two primary sources of conventional real-time corrections - beacon DGPS and Space-Based Augmentation System (SBAS). External corrections may also be input to the Vector PRO for situations where either internal correction services is not available or an external source is preferential.

In addition to the conventional differential positioning with internal sources of corrections, the Vector PRO also has a documented binary raw measurement protocol. A RINEX translator is available from CSI Wireless in the event that this may be useful, in addition to some C code snippets to aid in integrating the binary format itself into your own application.

For heading determination, the Vector PRO uses a moving base station RTK solution. This allows for a very precise computation of heading regardless of whether or not the receiver is in differential mode using either internal source of corrections or those from an external source.


Conventional Real-Time Differential The majority of GPS navigation and positioning uses this form of positioning. Conventional real-time differential techniques are more robust in their usage and versatility than post processing or RTK solutions. They are tolerant to errors in communication of the real-time corrections from the base station or correction network, provide a reasonable amount of accuracy (sub-meter accuracy is best-case), and can be simply turned on and used without too much regard other than ensuring a lock to GPS satellite signals and the correction communication link.

How it Works

Conventional DGPS involves setting up a reference GPS receiver at a point of known coordinates. This receiver makes distance measurements, in real-time, to each of the GPS satellites. The measured ranges include the errors present in the system. The base station receiver calculates what the true range, without errors, knowing its coordinates and those of each satellite. The difference between the known and measured range for each satellite is the range error. This error is the amount that needs to be removed from each satellite distance measurement in order to correct for errors present in the system.

The base station transmits the range error corrections to remote receivers in real-time. The remote receiver corrects its satellite range measurements using these differential corrections, yielding a much more accurate position. This is the predominant DGPS strategy used for a majority of real-time applications. Positioning using corrections generated by DGPS radiobeacons will provide a horizontal accuracy of 1 to 5 meters with a 95% confidence. More sophisticated, short-range DGPS systems (10 to 15 km) can achieve centimeter-level accuracy, but are expensive and often limited to precise survey applications due to technical constraints on their use.


DGPS Format

For manufacturers of GPS equipment, commonality is essential to maximize the utility and compatibility of a product. The governing standard associated with GPS is the Interface Control Document, ICD-GPS-200, maintained by the US DoD. This document provides the message and signal structure information required to access GPS.

Like GPS, DGPS data and broadcast standards exist to ensure compatibility between DGPS services and associated hardware and software. The Radio Technical Commission for Maritime Services Special Committee 104 has developed the primary DGPS standard associated with conventional DGPS, designated RTCM SC-104 V2.2. This correction standard is used by many correction services, including many private reference stations and DGPS beacon systems. The Vector PRO smart antenna supports this correction protocol via either of its two serial ports.

In addition to the RTCM standard, the Radio Technical Commission for Aeronautics has a differential service intended for wide area correction services, designated RTCM SC-159. The United States Federal Aviation Administration’s Wide Area Augmentation System (WAAS) and other compatible Space Based Augmentation Systems (SBAS) such as the European Geostationary Navigation Overlay System (EGNOS) and the Japanese MT-SAT Satellite-based Augmentation System (MSAS) use this data format. The Vector PRO system is compatible with each of these differential services.

Note - When using a differential correction service, the resultant position may be referenced to a local datum rather than the WGS-84 ellipsoid. Please refer to your signal provider for more information.

Post Processing


Post processing is a method to compute accurate positions in post mission by logging raw measurement data at the base station and the from the rover simultaneously. The differential processing can then be performed later in the office using sophisticated processing software tools. There are a small variety of methodologies available to the operator, such as static, rapid static, kinematic, etc.

Describing in detail the various post processing techniques is beyond the scope of this document, however, generally, post processing is more complicated from a procedural perspective and requires more skill to successfully operate than real-time systems.

Real-Time Kinematic (RTK) Real-Time Kinematic (RTK) is a term used for describing an advanced method of correcting for GPS errors. The differential method discussed in the previous section is a conventional real-time differential GPS process.

How it Works

Similar to conventional DGPS, RTK uses a base station (or a network of base stations) installed at locations of known coordinates. Measurements in real-time are taken at both the rover and base station, however, in addition to the C/A code-based range measurement, the carrier phase is also measured. The additional measurement of the carrier phase is used to compute the number of carrier cycles between the rover antenna and each of the satellites in view.

Computing the number of cycles to each satellite from the rover antenna is easier said than done, since both the base and the rover receivers can only measure the portion of the current wavelength being received (this is the angular carrier phase, measured in degrees from 0 to 360). This means that the number of full cycles, beyond the portion of the current one being received, can’t be directly measured in the same manner as the C/A code (through time alignment of a code copy


within the receiver). Some advanced methods of resolving the ambiguous number of carrier waves to each satellite (called the ambiguity for each satellite) is the job of proprietary algorithms within capable receivers.

There are two primary types of RTK based upon the type of ambiguity solution that they offer: an integer (a variable with no fractional wavelength) or a floating variable (a value with that also has a value beyond the decimal point). A floating integer solution can offer a designer more flexibility, but it does not provide as much accuracy as a fixed integer ambiguity solution. The Vector PRO uses a fixed integer ambiguity solution for computing real-time heading and is able to solve the integer ambiguities quickly with prior knowledge of the antenna separation. Data from the supplemental sensors also decreases the time required for a solution to be computed.

Moving Base Station RTK The technology at the heart of the GPS compass heading solution is a moving base station RTK solution. This RTK solution relies on high quality GPS antennas, supporting GPS receiver hardware, and sophisticated algorithms, which result in a 0.5? heading accuracy (90%).

How it Works

There are two GPS sensors inside the Vector PRO that share the same clock. One receiver is designated the base and the other the rover.

In conventional RTK systems where the base station is stationary and the rover positions away from the base station, there is a relationship between the two receivers that can be described in terms of an azimuth (a direction referenced to north) and separation from the base station to the rover. No matter where the rover moves, the relationship of position can still be described in this manner. Moving one step further, if the


base station is also moving, the relationship of relative position can still be described in this manner.

The Vector PRO’s base (primary) and rover (secondary) antennas are rigidly fixed in position relative to one another on a metallic bracket (the sum of the antennas and the bracket is referred to as the Vector Antenna Array). In the case of the Vector PRO being used on a marine vessel for heading, when differencing the measurements, only the relative motion of the rover antenna with respect to the base will remain. Since the separation between the two antennas remains fixed with the antenna bracket, the only change is the result of the heading change.

Factors Affecting DGPS Accuracy Many factors affect the positioning accuracy that a user may expect from a DGPS system. The most significant of these influences include:

• Proximity of the remote user to the reference station (atmospheric and orbit errors) • Age of the received differential corrections • Atmospheric conditions at the beacon and remote user locations • Satellite constellation geometry, often expressed as a Dilution of Precision (DOP) • Magnitude of GPS signal multipath present at the remote station • Quality of the GPS receiver being used at both the reference and remote stations

Proximity of the Reference Station

The distance between a remote user and the reference station can sometimes be considerable, such as when using 300 kHz DGPS radiobeacons. Consequently, some of the errors associated with GPS at the base station differ somewhat from those at the remote user’s location. This spatial decorrelation of errors can result in a relative position offset from the absolute coordinates of the remote receiver. This offset may be as much as one meter for every 100 km (62 miles) between the base station and remote receiver.


The causes of decorrelation are:

• GPS satellite orbit errors (significant) • Ionospheric errors (potential to be most significant depending on level of activity) • Tropospheric errors (less significant)

GPS satellite orbit errors are typically a greater problem with local area differential systems, such as that of radiobeacons. The decorrelation effect is such that the satellite’s orbit error projects onto the reference receiver and remote receiver’s range measurements differently. As the separation between the receivers increases, the orbit error will not project onto the ranges in the same manner, and will then not cancel out of the measurement differencing process completely. SBAS networks, with the use of multiple base stations, are able to accurately compute the orbit vector of each satellite. The resulting corrector is geographically independent, so minimal decorrelation occurs with respect to position within the network.

The ionosphere and the troposphere both induce measurement errors on the signals being received from GPS. The troposphere is the humid portion of the atmosphere closest to the ground. Due to it humidity, refraction of GPS signals at lower elevations can distort the measurements to satellites. This error source is rather easily modeled within the GPS receiver and doesn’t constitute a significant problem.

The error induced by the ionosphere is more significant, however, is not as simple a task to correct. The ionosphere is charged layer of the atmosphere responsible for the Northern Lights. Charged particles from the sun ionize this portion of the atmosphere, resulting in an electrically active atmospheric layer. This charged activity affects the GPS signals that penetrate this layer, affecting the measured ranges. The difficulty in removing the effect of the ionosphere is that it varies from day to day, and even hour to hour due to the sun’s 11-year solar cycle and the rotation of the earth, respectively. During the summer of 2001, the sun’s solar cycle reached an 11-year high and going forward we will see a general cooling trend of the ionosphere over the next few years thus reducing ionospheric activity.


Removing the effect of the ionosphere depends on the architecture of the differential network. DGPS radiobeacons, for example, use a more conventional approach than WAAS or SBAS in general. DGPS beacons make use of a single reference station, which provides real-time GPS error corrections based upon measurements that it makes at its location. It’s possible that the state of the ionosphere differs between the remote user and the single reference station. This can lead to incompletely corrected error source that could degrade positioning accuracy with increased distance from the base station.

WAAS and SBAS use a different approach, using a network of reference stations in strategic locations to take measurements and model the real-time ionosphere. Updates to the ionospheric map are sent on a continual basis to ensure that as the activity of the ionosphere changes with time, the user’s positioning accuracy will be maintained. Compared to using a DGPS beacon, the effect of geographic proximity to a single reference station is minimized resulting in more consistent system performance throughout all locations within the network.

Correction Latency

The latency of differential corrections to a lesser extent affects the achievable positioning accuracy at the remote receiver since the magnitude of SA was turned to zero in year 2000. Latency is a function of the following.

• The time it takes the base station to calculate corrections • The data rate of the radio link • The time it takes the signal to reach the user • The time required for the remote differential receiver to demodulate the signal and communicate it to the GPS receiver. • Any data loss that occurs through reception problems

Most of these delays require less than a second, though in some instances, depending upon the amount of information being transferred, overall delays of three to five seconds may occur. The effect of latency is mitigated by new COAST technology within the Vector PRO. This technology is especially valuable in conditions of DGPS signal loss


where the age of corrections increases for each second of signal loss. Consult Section 1.7 for further information on COAST.

Satellite Constellation Geometry

The number of satellites visible and their geometry in the sky influences positioning accuracy. The Dilution of Precision (DOP) describes the strength of location and number of satellites in view of the receiver. A low DOP indicates a stronger potential for better accuracy than a high DOP. Generally, more satellites visible to both the reference and remote receivers will provide a lower DOP (any satellites seen by either receiver and not the other, are not used in the position solution). Additionally, if the satellites are evenly spread around the receiver, rather than grouped in a few regions of the sky, a lower DOP (stronger solution) will result.

GPS Signal Multipath

Satellite signals received by the GPS receiver by a reflection from an object can decrease positioning accuracy. These multipath signals increase the measured range to a satellite as the signal takes a longer route to the GPS antenna. Certain precautions will minimize GPS antenna sensitivity to these reflected signals. Operating away from large reflective structures such as buildings or using special antennas and GPS equipment can help to reduce the impact of multipath. For most consumer-level applications, a small amount of multipath is tolerable.

GPS Receiver Quality

The quality of a GPS receiver has a dramatic influence on positioning accuracy. Consumer-based GPS products, such as many affordable handheld and fixed-mount receivers, typically operate with an accuracy of 3 to 5 meters horizontally 95% of the time. The accuracy of a particular product depends on the specific receiver’s performance characteristics. Higher accuracy GPS receivers are able to achieve


sub-1 meter horizontal accuracy 95% of the time using real-time DGPS transmissions. The Vector PRO system falls in to this latter category.

Space Based Augmentation Systems The US Federal Aviation Administration is in the process of developing a Wide Area Augmentation System (WAAS) for the purpose of providing accurate positioning to the aviation industry. In addition to providing a high quality, accurate service for this industry, this service is available free of charge to all other civilian users and markets in North America. This service falls into the greater category of Space Based Augmentation System (SBAS).

Upon the successful completion of a 21-day test on August 24, 2000, the FAA announced that WAAS would be running 24 hours per day, seven days per week from then on. Testing has shown since that this signal is accurate and reliable, however, since no official statement regarding its Initial Operating Capability has been issued, this signal is to be used at your risk.

Other government agencies are in the process of developing compatible SBAS systems for their respective geographic regions. In Europe, the European Space Agency, the European Commission, and EUROCONTROL are jointly developing the European Geostationary Overlay System (EGNOS). In Japan, the MTSAT Satellite-based Augmentation System (MSAS) is in progress of development by the Japan Civil Aviation Bureau (JCAB). China has a similar program for a SBAS and the service is named the Chinese Satellite Navigation Augmentation System (SNAS). The Vector PRO is capable of receiving correction data from all compatible SBAS.

EGNOS is currently in a prototyping phase, referred to as the EGNOS System Test Bed (ESTB) and which has been broadcasting a test signal since February 2000. EGNOS should be used at your risk only. MSAS has yet to begin transmitting data publicly. SNAS is transmitting correction data currently on a military communication channel and is expected to become publicly available in the near future.


Warning - Although WAAS has successfully passed a 21-day test, and is publicly available; its use is at your risk and discretion. EGNOS is not currently broadcasting with any form of certification or approval, may produce misleading information, and its use is entirely at your risk and discretion.

MSAS may begin broadcasting a preliminary signal as early as the end of 2003.

How it Works

A SBAS incorporates a modular architecture, similar to GPS, comprised of a Ground Segment, Space Segment, and User Segment.

• The Ground Segment includes reference stations, processing centers, a communication network, and Navigation Land Earth Stations (NELS) • The Space Segment includes geostationary satellites (For example, WAAS and EGNOS use Inmarsat-III transponders) • The user segment consists of the user equipment, such as the Vector PRO

A SBAS uses a state-based approach in their software architecture. This means that a separate correction is made available for each error source rather than the sum effect of errors on the user equipment’s range measurements. This more effectively manages the issue of spatial decorrelation than some other techniques, resulting a more consistent system performance regardless of geographic location with respect to reference stations.

Specifically, SBAS calculates separate errors for the following.

• The ionospheric error • GPS satellite timing errors • GPS satellite orbit errors

Provided that a GPS satellite is available to the SBAS reference station network for tracking purposes, orbit and timing error corrections will be available for that satellite. Ionospheric corrections for that satellite are only available if the signal passes through the ionospheric map provided


by SBAS (for example, the WAAS ionospheric map covers the majority of North America). As an example, if a satellite is South of your current location at a low elevation angle, the pierce point of the ionosphere will be considerably South of your location since the ionosphere is at an altitude of approximately 60 km. There must be sufficient ionospheric map coverage beyond your location in order to have ionospheric correctors for all satellites.

To enhance the information provided by SBAS, the Vector PRO system extrapolates the ionospheric information beyond the broadcast information. This increases the usable geography for WAAS and is discussed in Section 1.5.5. This feature helps to improve the usable coverage area of a SBAS service.

Signal Information

A SBAS transmits correction data on the same frequency as GPS from a geostationary satellite (the space segment), allowing the use of the same receiver equipment used for GPS. Another advantage of having SBAS transmit on the same frequency is that only one antenna is required.

Reception

Since SBAS broadcast in the L-band, the signal requires a line of sight in the same manner as GPS to maintain signal acquisition.

Currently, two commercial marine communication satellites are transmitting WAAS data for public use, and one each is located above both the Pacific Ocean and Northern Brazil. Due to their location, these satellites may appear lower on the horizon, depending on your geographic position on land. In regions where the satellites appear lower on the horizon, they may be more prone to being masked by terrain, foliage, buildings or objects, resulting in signal loss. The further that you are away from the equator and the satellite’s longitude will cause the satellite to appear lower on the horizon. Fortunately, the SI-TEX COAST Technology helps alleviate this problem by maintaining


system performance when WAAS (SBAS) signal loss occurs for extended periods of time. More information on COAST is provided in Section 1.7.

The EGNOS System Test Bed (ESTB), also referred to as EGNOS in this document, uses two geostationary satellites (separate from WAAS), however, in this case, they are located over the Atlantic and Indian Oceans. Similar to WAAS, the satellites may appear lower on the horizon, depending on your geographic position on land. The further that you are away from the equator and the satellite’s longitude will cause the satellite to appear lower on the horizon. If the EGNOS signal becomes unavailable due to obstruction, COAST technology helps to maintain system performance during times of differential outage.

When using SBAS correction data, the Vector PRO is able to provide you with the azimuth and elevation of the SBAS available satellites via a NMEA serial port command to aid in determining their position with respect to the built-in antenna. More about this feature is described in Section 5.5.2.

WAAS and ESTB Coverage

Figure 1-3 depicts the current WAAS coverage as provided by the currently leased Inmarsat Atlantic Ocean Region - West (AOR-W) and Pacific Ocean Region (POR) geostationary satellites. This figure approximates signal coverage with white shading where each satellite is 5? elevation or greater. Figure 1-3 also shows additional contours for 10?, 15?, and 20? elevations. Within the white shaded coverage area, at least one of the two satellites is available by line of sight. Within the overlap area, both satellites may be accessible. Although there is geographic coverage at higher latitudes, practical usage of WAAS will be limited to environments where a relatively consistent line of sight to either of the Inmarsat satellites from the Vector PRO system.

Figure 1-4 presents approximate EGNOS System Test Bed coverage provided by the leased Inmarsat Atlantic Ocean Region - East (AOR-E) and Indian Ocean Region (IOR) satellites. This figure approximates signal coverage with white shading where each satellite is 5? elevation


or greater. Figure 1-3 also shows additional contours for 10?, 15?, and 20? elevations. Within the white shaded coverage area, at least one of the two satellites is available by line of sight. Within the overlap area, both satellites may be accessible. Virtually all of Europe, part of northern Africa, and into the Middle East is covered with at least one signal. Most of Europe is covered by two signals.

Note - Currently, only the AORE-E satellite is broadcasting. Refer to Appendix C - Resources for information on how to monitor the status of the ESTB.

Note - The satellite elevation angle lowers with increasing distance away from the equator and from the satellite’s longitude. Although a good amount of signal coverage is shown in Northern latitudes for both WAAS and EGNOS, it may not be usable due to its low elevation angle and the potential for it to be obstructed. Ideally, testing of the system in the area of its use is recommended to ensure that the signal is sufficiently available.

Note - The SBAS signal coverage may be present in some areas without either sufficient ionospheric map coverage or satellites with valid orbit and clock correctors. In such a case, differential positioning with SBAS may not be desirable or possible, as four or greater satellites (with correctors) must be available to compute a DGPS position. The next section provides further information on the ionospheric map features of SBAS and the Vector PRO.


Figure C-1 WAAS Coverage


Figure C-2 EGNOS Coverage


SBAS Ionospheric Map Extrapolation

To improve upon the ionospheric map provided by SBAS, the Vector PRO extrapolates a larger ionospheric map from the broadcast coverage map, extending its effective coverage. This allows the Vector PRO to be used successfully in regions that competitive products may not.

For WAAS, this is especially important in Canada for regions north of approximately 54? N latitude and east of 110? W longitude. Extrapolation also provides enhanced coverage throughout much of the Gulf of Mexico.

Please note that the process of estimating ionospheric corrections beyond the WAAS broadcast map would not be as good as having an extended WAAS map in the first place. This difference may lead to minor accuracy degradation.

Figures 1-1 and 1-2 depict the broadcast WAAS ionospheric map extent and the CSI Wireless extrapolated version, respectively. As can be seen from Figure 1-2, the coverage compared to Figure 1-1 extends further in all directions, enhancing usable coverage.

Similar to the WAAS ionospheric map extrapolation, Figures 1-3 and 1-4 depict the broadcast EGNOS ionospheric map extent and the SI-TEX extrapolated version, respectively. As can be seen from Figure 1-2, the coverage compared to Figure 1-1 extends further in all directions, enhancing usable coverage.


Figure C-3 Broadcast WAAS Ionospheric Correction Map

Figure C-4 Extrapolated WAAS Ionospheric Correction Map


Figure C-5 Broadcast EGNOS Ionospheric Correction Map

Figure C-6 Extrapolated EGNOS Ionospheric Correction Map


Radiobeacon DGPS Many Marine authorities, such as Coast Guards, have installed networks of radiobeacons that broadcast DGPS corrections to users of this system. With the increasing utility of these networks for terrestrial applications, there is an increasing trend towards densification of these networks inland.

Radiobeacon Range The broadcasting range of a 300 kHz beacon is dependent upon a number of factors including transmission power, free space loss, ionospheric state, surface conductivity, ambient noise, and atmospheric losses.

The strength of a signal decreases with distance from the transmitting station, due in large part to spreading loss. This loss is a result of the signal’s power being distributed over an increasing surface area as the signal radiates away from the transmitting antenna.

The expected range of a broadcast also depends upon the conductivity of the surface over which it travels. A signal will propagate further over a surface with high conductivity than over a surface with low conductivity. Lower conductivity surfaces such as dry, infertile soil, absorb the power of the transmission more than higher conductivity surfaces, such as sea water or arable land.

A radiobeacon transmission has three components: a direct line of sight wave, a ground wave, and a sky wave. The line of sight wave is not significant beyond visual range of the transmitting tower, and does not have a substantial impact upon signal reception.

The ground wave portion of the signal propagates along the surface of the earth, losing strength due to spreading loss, atmospheric refraction and diffraction, and attenuation by the surface over which it travels (dependent upon conductivity).

The portion of the beacon signal broadcast skywards is known as the sky wave. Depending on its reflectance, the sky wave may bounce off the ionosphere and back to Earth causing reception of the ground wave


to fade. Fading occurs when the ground and sky waves interfere with each other. The effect of fading is that reception may fade in and out. However, this problem usually occurs in the evening when the ionosphere becomes more reflective and usually on the edge of coverage areas. Fading is not usually an issue with overlapping coverage areas of beacons and their large overall range.

Atmospheric attenuation plays a minor part in signal transmission range, as it absorbs and scatters the signal. This type of loss is the least significant of those described.

Radiobeacon Reception Various sources of noise affect beacon reception, and include:

• Engine noise • Alternator noise • Noise from Power lines • DC to AC inverting equipment • Electric devices such as CRT’s electric motors, and solenoids Noise generated by this type of equipment can mask the beacon signal, reducing or impairing reception. Section 2.4.1 presents an effective procedure to minimize impact of local noise on beacon reception when using this correction service.

Radiobeacon Coverage Figure C-7 shows the approximate radiobeacon coverage throughout the world. In this figure, light shaded regions note current coverage, with beacon stations symbolized as white circles.


Figure C-7 World DGPS Radiobeacon Coverage

The world beacon networks continue to expand. For more current coverage, consult the CSI Wireless Web site at:

www.csi-wireless.com.

DGPS Service Comparison As the Vector PRO offers the use of two internal differential services, questions have been raised in regards to which correction source to use when more than one is available. Depending on your local legislation and vessel size, you may be required to use beacon corrections exclusively when approaching harbors or navigating in specific waterways. It is your responsibility to know what these regulations are and if you need to comply with them. By default, the Vector PRO uses SBAS corrections.

This second provides a brief comparison of beacon and SBAS services in the event that you are able to choose which service that you wish to use.


Beacon signals are not affected by a line of sight. In situations where there are tall obstacles that may block the line of sight SBAS, such as buildings, bridges, other vessels, etc. However, the value of our COAST technology is that outages of the DGPS signal are less of an influence on performance. This improves the robustness of using a line of sight signal in areas of potential blockage. If robustness to signal acquisition due to line of sight is considered a significant issue, beacon DGPS should be considered in replace of SBAS services.

Both beacon and SBAS services use base stations to calculate GPS correction data. Beacons use a single, local base station for corrections, while SBAS services use a wide area network of stations. If there is a significant distance to the closest beacon (greater than a 200 - 300 hundred miles), this will have an effect on positioning accuracy due to differing environmental conditions between the remote receiver and base station (spatial decorrelation). In such a case, if the accuracy degradation is not tolerable, SBAS should be considered. However, if you are operating at distances significantly away from the SBAS network, the same issue of spatial decorrelation can occur.

Beacon signals are more susceptible to radio frequency interference than SBAS signals, however the state of SI-TEX beacon technology has progressed such that beacon systems provide very good immunity to environmental noise. If RF noise presents a continuing problem with your installation, you should first try relocating the Vector PRO away from sources of noise. If this doesn’t solve the problem, consider using SBAS.

Both SBAS and beacon services are free, so it’s possible to use both for a period of time, to determine which satisfies your needs best. Once this has been determined, it’s a good idea to continue using one of the two services from then on, and not switch from between the services frequently. This will help to ensure consistent positioning from day to day. For information relating to locations of DGPS beacons, please consult our web site at:



Appendix C - Resources

Specifications National Marine Electronics Association, National Marine Electronics Association (NMEA 0183) Standard for Interfacing Marine Electronic Devices, Version 2.1, October 15, NMEA 1995, PO Box 50040, Mobile Alabama, 36605 USA, Tel: +1-205-473-1793, Fax: +1-205-473-1669

Radio Technical Commission for Maritime Services, RTCM Recommended Standards for Differential NAVSTAR GPS Service, Version 2.2, Developed by Special Committee No. 104, RTCM 1998, 1800 Diagonal Rd, Suite 600, Alexandria, VA, 22314-2840 USA, Tel: +1-703-684-4481, Fax: +1-703-836-4429

Radio Technical Commission for Aeronautics, Minimum Operational Performance Standards (MOPS) for Global Positioning System/Wide Area Augmentation System Airborne Equipment, Document RTCA DO-229A, Special Committee No. 159, RTCA 1998, 1828 L Street, NW, Suite 805, Washington, DC, 20036 USA, Tel: +1-202-833-9339

ARIC Research Corporation, Interface Control Document, Navstar GPS Space Segment / Navigation User Interfaces, ICD-GPS-200, April 12, 2000, 2250 E. Imperial Highway, Suite 450, El Segundo, CA 90245-3509, www.navcen.uscg.gov/gps/geninfo/default.htm

CSI Web Site This following address is the CSI Wireless Web site which provides detailed information on this product.



FAA WAAS Web Site This site offers general information on the WAAS service provided by the U.S. FAAS.

gps.faa.gov/Programs/WAAS/waas.htm

WAAS Broadcast Schedule Web Site This site provides detailed information relating to the WAAS service broadcast schedule.

wwws.raytheontands.com/waas/

ESA EGNOS System Test Bed Web Site This site contains information relating to past performance, real-time performance, and broadcast schedule of EGNOS

www.esa.int/export/esaEG/estb.html

Solar and Ionospheric Activity Web Sites The following sites are useful in providing details regarding solar and ionospheric activity.

iono.jpl.nasa.gov//latest.html

iono.jpl.nasa.gov//gim_dailymovie.html

www.spaceweather.com

www.maj.com/sun/noaa.html


Index

$ $GPGGA, 130 $GPGLL, 131 $GPGSA, 132 $GPGST, 133 $GPGSV, 134 $GPMSK, 143 $GPRMC, 135 $GPRRE, 136 $GPVTG, 137 $GPZDA, 138, 139 $J4STRING, 122, 123 $JAGE, 120 $JAIR, 105 $JALT, 107 $JAPP, 108 $JASC,D1, 105 $JASC,GP, 119 $JASC,RTCM, 128 $JASC,VIRTUAL, 106 $JBAUD, 110 $JBIN, 118 $JCONN, 110 $JDIFF, 111 $JGEO, 126 $JK, 112 $JOFF, 121 $JPOS, 112 $JQUERY,GUIDE, 113 $JRD1, 127 $JRESET, 114 $JSAVE, 114 $JSHOW, 114 $JT, 117 $JWAASPRN, 125 $PCSI,1, 145

A Accuracy, 203, 204, 206

B Background Search (beacon), 88 Baud Rate, 80 Beacon

Receiver Performance, 89 Beacon Receiver

Signal to Noise Ratio (SNR), 89 Bit Error Rate (WAAS), 86

C Cable Interface, 28, 53 Cables

Antenna, 74 CDA-2MAX

Antenna Placement, 54 Routing and Securing Cable, 74

COAST Feature, 89 Customer Service, xxiii

D Default NMEA Message Output, 82 Default Parameters, 80 DGPS Errors, 203

Age of Correction, 206 Geometry, 206 Latency, 206 Multipath, 207 Proximity, 204

Differential Corrections, 199 Differential GPS (DGPS), 199, 200


G Global Search (beacon), 87 GPS, 200

H Humidity, 55

I ICD-GPS-200, 200 Installation

Environmental Considerations, 55 Placement, 54 Power Considerations, 55

M Multipath, 207

N NMEA 0183, 94, 101 NMEA 0183 Command

Partial Manual Tune, 143 NMEA 0183 messages, 101 NMEA 0183 Query

Reserved, 145 NMEA 0183 Response

Performance Status, 144

P PocketMAX, 99

Positioning Accuracy, 84

R RTCM SC-104, 200

S SBAS Performance, 86 Selective Availability (SA), 197 Serial Port Defaults, 81 Signal to Noise Ratio (SNR), 89

T Temperature, 55 Troubleshooting, 192 Tune Mode

Automatic Beacon Search (ABS), 87, 88

Manual, 88 WAAS Automatic Tracking, 85

U Update Rates, 85

W WAAS

Bit Error Rate, 86 Receiver Performance, 86

WGS-84, 197 www.csi-wireless.com, xxiv

Documents

Vector PRO Manual for SI-TEX PDF 4-07 - Hodges Marinecdnstatic.hodgesmarine.com/productmanuals/SITVECTORPRO-15.pdf · • DGPS service provider performance specifications. ... 1.7