An Approach to Implementation of Rangeless GPS Tracking

An Approach to Implementation of Rangeless GPS Tracking

ITEA 2016 Test Instrumentation Workshop, Session #3

John R. Dodd12 May 2016

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When It Has To Be Right The First Time

Outline

Requirement

Generic Solution

Specific Implementation

― Logger Units

― Aircraft Installation

― Gateway Interface

― Visualization

Issues/Considerations

Future Improvements

Questions

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Requirement

Provide vehicle (air, ground, surface, human) tracking in a pre-existing non-instrumented environment.

Provide real-time generation of Time-Space Position Information (TSPI) over land/water.

― Differential GPS accuracy

― Open-air transmission

Support system-level Test and Evaluation:

― Controlled, limited number of participant vehicles

― Clear line of sight (LoS)

Rapid deployment (setup, operation, tear-down).

Independent, non-intrusive, and reliable operation:

― COTS components

Classified/unclassified TSPI data-sharing to other systems

― Scalable distance/data relay

― On-board logging/removable media

― Low depot maintenance

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Requirement

TSPI:

― .CSV on-board

― Data-sharing

(downlink):

• CoT

• DIS

• KML

• tbd

― 1-10 Hz

Description Units Type Example -------------------------------------------------------------------------------------------------------------------------

DL500 ID 0-65535 int 1

Record date time UTC char 10/29/2003 20:02:28

position latitude WGS84 float +/-35.1309351 (+ = North)

position longitude WGS84 float +/-106.6279589 (- = West)

MSL position altitude m float +1523.39

velocity east-west m/sec float 47.93

velocity north-south m/sec float -70.29

velocity up-down m/sec float -0.21

Mag orientation azimuth deg float 0.00

orientation elevation deg float 0.00

orientation rotation deg float 0.00

trigger event count int 508

trigger time expired sec float +57.1234

GPS health hex char 0 = Good, else bad

GPS error hex char 0

DGPS status int 3=DGPS, 2=GPS

Magnetometer status hex char 0

ECEF X m float -2215093.71

ECEF Y m float -4907126.69

ECEF Z m float 3446343.78

ECEF Vx m/sec float -11.46

ECEF Vy m/sec float -43.44

ECEF Vz m/sec float -48.72

# of Active Satellites int

Satellite 1…N ID int 20, else empty

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Generic Solution

Vehicle logger unit consisting of:

― GPS receiver with antenna for GPS satellite reception. (Optionally: receiver should be WAAS capable.)

― Radio modem with antenna for uplink/downlink communications with ground station (VHF/UHF).

― Microprocessor for timing, formatting/managing data communications, error correction, and media recording.

Ground station logger unit consisting of:

― GPS receiver with antenna for GPS satellite reception.

― Radio modem with antenna for uplink differential correction and downlink of TSPI communications with vehicle unit(s).

― Interface/port (serial/USB) for connection to laptop gateway host.

― GPS fixed-site beacon receiver for differential correction.

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Generic Solution

Ground station gateway application for interface, downlink data translation to common format and data sharing with user systems:

― Example messaging protocols are Distributed Interactive Simulation (DIS) and Cursor on Target (CoT).

― Translated TSPI transmitted to users via Ethernet (fixed LAN but could also be wireless)

― Example user systems are Common Operating Picture (COP), Command and Control (C2) system, Blue Force Tracker, analysis applications, etc.

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Generic Solution

Ground

Station Unit

GPS

ConstellationVehicle

Logger Unit

Remote

Fixed GPS

Beacon Site

Differential

TSPI

Downlink

Error

Correction

Uplink

LAN

TSPI Broadcast (DIS, CoT, etc.)

User Systems

COP

C2

SystemCorrection

Data

TSPI

Formatting

Gateway

TSPI Processing

1GPS Satellite

Positions

2

3

4

5

6

Note: WAAS Satellites transmit

correction data, eliminating

need for fixed beacon site

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AMERICAN SYSTEMS’ solution for the vehicle and ground station logger is the DL-500 GPS Logger, comprised of COTS components.

We have developed/improved/refreshed the DL-500 over the last 10+ years to support T&E field requirements.

The current generation of the DL-500 Logger uses primary hardware/software components:

― Radio modem: Teledesign TS-4000 (UHF and VHF versions)

― GPS receiver: ublox MAX-7W GPS/GNSS Module

― Microcontroller (with integrated firmware): Persistor® PERCF2IM 68332-based controller/logger

― Antennas, cabling, battery, beacon receiver, plates, etc.

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UHF antenna for

Base Station

VHF & UHF Antennas and UH-60 Mounting Plates


Vehicle Logger Unit

VHF antenna for

Base Station

Ground Station Logger Unit

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Specific Implementation (DL-500 Front View)

Status light not shown

• Solid light – no GPS

• Blinks on 1 second interval – GPS w/o Compact Flash card

• Blinks on 5 second interval – GPS & Compact Flash installed

The mode switch should be Operational (down as shown in the image)

Unit must be reset if the mode is changed accidently

Power

Switch

Mode Reset

Compact

Flash

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Specific Implementation (DL-500 Rear View)

RF Antenna

Connection GPS Antenna

Connection

PC Serial Cable

Connection

Power (battery or DC) DGPS Receiver

Connection

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Specific Implementation (Aircraft Installation)

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Specific Implementation (Gateway Interface)

The DL-500 Gateway interfaces the ground station unit to external user systems:

― Runs on a laptop

― Converts downlink TSPI

to user-desired protocol

• DIS

• CoT

• KML

― Transmits protocol TSPI to user systems via Ethernet LAN

― Monitors the status of the vehicle units

Ground Station

Logger Unit

DL-500

GatewayUser

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Specific Implementation (Visualization)

AMERICAN SYSTEMS visualizes DL-500 TSPI in real-time with two separate applications:

― Modular Analysis and Test Support System (MAnTSS)

― KML Display Tool (KDT)

MAnTSS is a multi-functional analysis suite (scenario generator, record, replay, 2D/3D visualization, network gateway, data translation, data reduction/analysis).

KDT is based on the free Google Earth® viewer available from Google fed by our own input interface.

Both applications are consumers of the TSPI transmitted by the DL-500 Gateway.

MAnTSS accepts DIS protocol, while KDT accepts KML.

Ground Station

Logger Unit

DL-500

Gateway

Visualization

MAnTSS

KDT

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Issues/Considerations

Range Frequency Approval (RFA)

Spectrum management/interference

FCC license for operation in Continental US

Line of sight placement of ground antennas

Data transmission relays for extended range

Airworthiness Release (AWR)

Network classification/equipment configurations

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Future Developments/Improvements

Disposable Logger:

― Functional prototype exists

― No-maintenance/throw-away logger

― 6.6 oz.; 4” x 3” x 1.5”

― Records 1Hz WAAS GPS to SD card

― Can interface to host datalink and power,

else operates in passive mode

― 9V battery/4hr life

DL-500 in UAV Crash

Prototype

Disposable Logger

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Future Developments/Improvements

Mobile differential beacon-site:

― DL-500 Beacon-receiver implementation requires surveyed fixed site transmitter.

― Limited number of transmitter sites, only in continental US.

― Current beacon receiver, Hemisphere GNSS R330, has capability to self fix.

― Requires testing and possible interface/

message communication changes to

microcontroller firmware.

― Would provide capability for differential

GPS accuracy world wide, without using

another GNSS (GLONASS, Galileo, etc.)

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Back-up

Slides

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Slick Sheets (Data Logger and MAnTSS)

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Teledesign TS-4000

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Slick Sheets (ublox MAX-7W GPS/GNSS Module)

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Slick Sheets (Hemisphere GNSS R330)

Documents

An Approach to Implementation of Rangeless GPS Tracking