Modernization and GPS III

Southern California Section ION Meeting

11 March 2009

Lt Col David Goldstein, US Air ForceChief EngineerGPS Wing

This briefing is for information only. 

2

Overview

• GPS SS Current Status– Overview of Current Space Segment Status

• Modernization Improvements– IIR-M, IIF, IIIA

• GPS III– Discussion will focus on GPS III

• Summary

3

GPS – Serving the World

• Constellation– the largest ever - 31 Healthy Satellites– 13 Block IIA– 12 Block IIR– 6 Block IIR-M– 31st satellite, SVN 23, set healthy, achieved 31

healthy satellite constellation for first time ever

• Most Recent Launch

– IIR-19(M) – 6th modernized SV

• Launched Wednesday, 15 Mar 08

• SVN 48, PRN 7

• Set healthy on 24 Mar 08

• Next Launches

– IIR-20(M) – Mar 09 – L5 demo payload

– IIR-21(M) – Aug 09

– IIF-1 – Oct 09

4

SPS Signal in Space Performance

System accuracy exceeds published standard

5

Block IIA/IIR Block IIIBlock IIR-M, IIF• Backward compatibility• 4th civil signal (L1C)• Increased accuracy• Increased anti-jam

power• Increased availability• Increased integrity

IIR-M: IIA/IIR capabilities plus

• 2nd civil signal (L2C)

• M-Code (L1M & L2M)

IIF: IIR-M capability plus

• 3rd civil signal (L5)

• 2 Rb + 1 Cs clocks

• 12 year design life

Basic GPS

• Standard Service

• Single frequency (L1)

• Coarse acquisition (C/A) code navigation

• Precise Service

• Y-Code (L1Y & L2Y)

• Y-Code navigation

Increasing System Capabilities Increasing Defense / Civil Benefit

GPS Modernization Program

6

Second Civil Signal (L2C)

• Designed to meet commercial needs– Higher accuracy via ionospheric correction

– Expected to generate over $5 billion in user productivity benefits

• Available since 2005• On 24 satellites by 2016

Increases accuracyfor consumers

Supports miniaturization, possible indoor use

Benefits existing professional receivers

7

Third Civil Signal (L5)

• Designed to meet demanding requirements for transport safety– Uses highly protected Aeronautical

Radionavigation Service (ARNS) band

• May also enable global, decimeter-level accuracy using new techniques

• Opportunity for international interoperability

• Demonstration signal to be launched in 2009

• 24 satellites by 2018

8

Fourth Civil Signal (L1C)

• Designed with international partners for interoperability

• Modernized civil signal at L1 frequency– More robust navigation across a broad

range of user applications– Improved performance in challenged

tracking environments– Original L1 C/A signal retained for

backward compatibility

• Launches with GPS III A in 2014• On 24 satellites by ~2021

Under trees

Inside cities

9

New Civil Signals Summary

• Second civil signal “L2C”– Designed to meet commercial needs

– Higher accuracy through ionospheric correction

– 1st launch: Sep 2005 (GPS IIR-M); 24 satellites: ~2016

• Third civil signal “L5”– Designed to meet demanding requirements for transportation safety-

of-life

– 1st launch: ~ 2009 (GPS IIF); 24 satellites: ~2018

• Fourth civil signal “L1C”– Designed with international partners for GNSS interoperability

– Begins with GPS Block III

– 1st launch: ~2014; 24 satellites: ~2021

10

GPS – Spectrum

RNSS Band RNSS Band RNSS 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

-230

-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(6 SVs)

(artist’s concept)

Planned

Previous

1575.421227.6Frequency (MHz)

1176.45

-250

-240

-230

-220

Pow

er S

pect

rum

(dBW

/Hz) L1C

Block IIR1997

11

GPS III Update

• Contract for GPS III-A satellites awarded, May 2008– Lockheed making excellent progress toward

PDR, 19/71 milestones

– Selective Availability feature to be eliminated

• Next-Generation Operational Control Segment (OCX)– Needed for Block III satellites & full functionality

of modernized signals

– Will implement full functionality of L2C and L5

– Awarded Phase A contracts to Northrop Grumman and Raytheon, Nov 2007

• Future increments of GPS III will incorporate additional capabilities– As technology matures and new requirements

are validated

12

GPS III- Spiral Development

• GPS III developed as a low risk capability insertion

program

• GPS III A– Provides initial capability for GPS III, new signals, added power

• GPS III B– Directional crosslinks demonstration

• Enhanced ranging

• Enhanced integrity

• GPS III C– Spot Beam demonstration

• Enhanced anti-jam capability

13

Summary

• Largest constellation in history with best accuracy ever

• GPS III A design phase successfully moving forward

• GPS III will provide modernized design and technology insertion– New signal design– Increased availability– Increased integrity– Increased accuracy

GPS – Serving the World