GPS Status and Modernization

Munich Satellite Navigation SummitMunich, Germany

20 Feb 2008

Lt Col Harold Martin, US Air Force

PNT Command Lead

Air Force Space Command

This briefing is for information only.  No US Government commitment to sell, loan, lease, co-develop or co-produce defense articles or provide defense services is implied or intended.

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Overview

• GPS Status• Recent Modernization Improvements• The Future• Summary

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GPS – Serving the World

• Constellation– the largest ever- 30 Healthy Satellites

• 13 Block IIA• 12 Block IIR• 5 Block IIR-M• 31st satellite, SVN 23, still has a good clock –

AF working to see if it can be set healthy to achieve 31 healthy satellite constellation for first time ever

• Most Recent Launch

• IIR-18(M) – 5th modernized SV

• Launched Wednesday, 20 Dec 07

• SVN 57, PRN 29, slot C1

• Set healthy on 2 Jan 08

• Next Launches

• IIR-19(M) – Mar 08

• IIR-20(M) – Jun 08 – L5 demo payload

• IIR-21(M) - Sep 08• IIF-1 launch in Spring 09

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GPS – Spectrum

ARNS Band RNSS Band ARNS Band

1575.421227.6

-250

-240

-230

-220

Pow

er S

pect

rum

(dB

W/H

z)

Frequency (MHz)

1575.421227.6Frequency (MHz)

1176.45

-250

-240

-230

-220

Pow

er S

pect

rum

(dB

W/H

z)

1575.421227.6

-250

-240

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-220P

ower

Spe

ctru

m (

dBW

/Hz)

Frequency (MHz)

P(Y) C/A

L5

ML2C

L1C

L1L2

L5

Block IIA1990

Block III, 2014

Block IIR-M, 2005

Block IIF, 2009

since Dec 2005(5 SVs)

(artist’s concept)

Planned

Previous

1575.421227.6Frequency (MHz)

1176.45

-250

-240

-230

-220

Pow

er S

pect

rum

(dB

W/H

z) L1C

Block IIR1997

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GPS Status – Serving the World

• Performance – Our best ever accuracy• Current Performance

Orbit SVN PRN URE Orbit SVN PRN UREA-1 39 9 1.81 D-1 61 2 0.33A-2 52 31 0.09 D-2 46 11 0.44A-3 38 8 0.72 D-3 45 21 0.43A-4 27 27 1.68 D-4 34 4 0.35A-5 25 25 0.46 D-5 24 24 0.59B-1 56 16 0.32 E-1 51 20 0.17B-2 30 30 0.97 E-2 47 22 0.14B-3 44 28 0.79 E-3 40 10 0.21B-4 58 12 0.19 E-4 54 18 0.24B-5 35 5 0.69 F-1 41 14 0.64C-1 57 29 0.09 F-2 55 15 0.27C-2 33 3 0.73 F-3 43 13 0.27C-3 59 19 0.26 F-4 60 23 0.7C-4 53 17 0.45 F-5 26 26 0.62

Source: JPL 2/10/2008

Average URE from 30 GPS SVs: 0.51 m

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GPS Status – Serving the World

• Recent Modernization Improvements:

• Launched 5th of 8 Block IIR-M satellites

• Architecture Evolution Plan – transition to a new Command and Control System at 2 SOPS for day-to-day operations

• Launch, Anomaly and Disposal Operations (LADO) - transitioned from 1 SOPS to 2 SOPS

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Recent Modernization Improvements

• 5 Block IIR-M Satellites on orbit now:• Second Civilian Signal, L2C

• L2C provides increased accuracy for civilian receivers: applications from precision farming to construction surveying

• 5th satellite means more L2C coverage around the globe

• Dual frequency receivers reduce ionospheric errors• Better performing atomic clocks than IIA• IIR-M 20 will fly a demonstration payload with an

L5 signal

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Recent Modernization Improvements

• Architecture Evolution Plan (AEP)• New Master Control Station operational Sep 14, 2007

• Modern distributed system replaced 1970’s era mainframe

• New Alternate Master Control Station at Vandenberg AFB, CA • Increased capacity to monitor satellites

• Utilizes dedicated Monitor Stations and NGA Monitor Stations to allow increased monitoring of GPS signals

• Increased worldwide coverage to 100 % (was 96.4%) and have 99.8% of world double covered

• Utilizes dedicated GPS Ground Antennas and allows use of 8 Air Force Satellite Control Network remote sites for increased commanding capability

• Increased worldwide commanding capability daily from 92.7% of the time to 94.5% while providing nearly double the backup capability

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Recent Modernization Improvements

• Launch, Anomaly and Disposal Operations (LADO)

• Transitioned capability from 1 SOPS to 2 SOPS - centralizes GPS operations into a single unit

• Replaces 90’s mainframe based system with increased use of modern distributed technology with electronic technical orders while decreasing the maintenance burden

• Used for launch of IIRM-17 on Oct 17, 2007 and IIRM-18 on Dec 20, 2007

The Future of GPS

GPS III (Block III)• Increased accuracy • Increased signal

strength• Signal integrity• Search and Rescue• Common Galileo

OS/GPS (L1C)

Legacy (Block IIA/IIR)• Basic GPS• C/A civil signal (L1C/A)• Std Pos. Service• Precise Pos. Service

• L1 & L2 P(Y) nav

Modernized (Block IIR-M)• 2nd civil signal (L2C)• M-Code signals (L1M, L2M)

SatellitesModernized (Block IIF) • 3rd civil signal (L5)

Upgraded (AEP)• IIR-M IIF TT&C• WAGE, AII, LADO• New MCS/AMCS

Legacy• TT&C• L1 & L2 monitoring

Control Systems

User EquipmentLegacy• Man Pack• MAGR, PLGR• RCVR-3A, 3S • OH, UH• FRPA, CRPA

Upgraded• DAGR• CSEL

• GAS-1• MAGR2K• GB-GRAM

Modernized• MUE• MSR

OCX Block 2 C2• L1C

OCX Block 1 (Modernized)• New Architecture• L2C, L5, M-Code• Flex Power

OCX Block 3/4)• Spot Beam • Mission Planning• Near-real Time Command

and Control

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Future of GPS – Block IIF Satellites

• Program Description• 2 Rb + 1 Cs clocks• 12 year design life• Launch Atlas V or Delta

IV• Satellite launch weight ~

3720 lbs

• PPS Signals: L1-L2 P(Y), L1-L2 M-code

• SPS Signals: L1 C/A, L2C, and L5

• L5 will provide second civil unique frequency in protected band

• Program Status:• SV1 in qualification tests• Delivery to Cape Dec 08• First launch 2009

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Future of GPS – Block III Satellites

• Program Description:• GPS IIIA includes all GPS

IIR-M/IIF capabilities, plus:• Enhanced earth coverage M-

code power (10x) enables improved operations in jammed & austere environments

• GPS III guarantees 4x better User Range Error than IIF

• GPS signal-in-space improves from <3m to <1m

• GPS III Integrity guarantee supports safety-of-life applications

• Probability of Misleading Signal-in-space Information (MSI) <0.0001/hr (Threshold)

• New L1C civil signal interoperable with Galileo/QZSS

• Aggressive Capability Insertion Program to mature capabilities

• Directional crosslink demo by IIIA; baselined on IIIB

• High Power Spot Beam demo by IIIB; baselined on IIIC

• Provides 20dB (100Xs) greater M-code power

• Program Status:• Implementing “Block” approach

to incrementally respond to warfighter capability requirements – reduces risk

• Contract in Source Selection, expect award Spring 08

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The Future of GPS – New C2 System

• Next Generation Operational Control Segment (OCX)• Enables modernized messaging • Controls more capable GPS constellation• Monitors all GPS signals• Two development contracts awarded – 21 Nov 07• Air Force Space Command (AFSPC) is standing up a Community

of Interest (COI) to implement net-centric operations using OCX• GPS COI is a forum for users to recommend the data and

services that should accessible from the global information grid (GIG)

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The Future of GPS – User Equipment

• Comm/Nav/Network Fusion• Benefit in comm/nav user equipment integration• Better accuracy, reduced time uncertainty, data

stripping, network interference detection/location• A variety of approaches to comm/nav integration exist

today and should be studied further• Additional investment and prototyping is required

• Chip Scale Atomic Clocks• Software defined receiver

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Summary

• Largest constellation in history with best accuracy ever

• Modernized Command and Control System allows more signal monitoring and quicker satellite commanding than ever before

• And we’re continuing to modernize and improve GPS even more!

GPS – Serving the World as the Gold Standard in Space Based Navigation