I n t e g r i t y - S e r v i c e - E x c e l l e n c e

Headquarters U.S. Air Force

GNSS Modernization Programand GPS Policies

Long-Term Considerationsfor Networks

Larry HothemAntarctic Remote Observatory Meeting

Boulder, CO19-20 Sept. 2004

GPS National Policy Review Constellation Status Modernization program New civil signals US-EC GPS-Galileo agreement Considerations for the Future Summary

GNSS Modernization Programand GPS Policies

Long-Term Considerations for Networks

Agriculture

Commerce State

Interior

NASAJoint Chiefs of Staff

Interagency GPS Executive Board (IGEB)

Defense Transportation

Established in 1996

GPS National Policy Review

Space-Based Positioning, Navigation, and Timing (PNT) Policy

The need for a revised policy Update and improve existing management mechanisms

for GPS and augmentations Recognizes that GPS has evolved into a global utility Need to focus more effectively on development,

acquisition, operation, sustainment, and modernization

Anticipate public release early Fall 2004 Replaces GPS policy adopted in March 1996

GPS National Policy Review Constellation Status Modernization program New civil signals US-EC GPS-Galileo agreement Considerations for the Future Summary

Constellation SummarySince 1 Jan 04

29 operational on-orbit satellites 3 satellites launched

SVN47(PRN22): 20 Dec 03 SVN59(PRN19): 20 Mar 04 SVN60(PRN23): 4 Jun 04

1 satellite disposed SVN13: 29 Apr 04

18 SVs past design life (7.5 years) 15 SVs past updated mean mission duration 13 SVs one component away from nav mission failure 8 SVs one component away from bus failure

Constellation Status Summary

DESPITE AGE AND COMPONENT ISSUES, THE CONSTELLATION IS EXCEEDING EXPECTATIONS

BY PROVIDING SOLID NAVIGATION AND TIMING PERFORMANCE

GPS Space and ControlClock and Reaction Wheel Performance Status(as of 1 Aug 2004)

39A (09) 06/93

25A (25) 02/92

1

2

SLOT

3

4

5

PLANE

A C D E F

2 3 41

SVN (PRN)

2 3 41Clock*Wheel* II/IIA = Rb, Rb, Cs, Cs IIR = Rb, Rb, RbDiagonal Line = Unhealthy

launchdate

38A (08) 11/97

56R (16) 1/03 36A (06) 03/94

33A (03) 03/96

59R (19) 03/04

24A (24) 07/91

46R (11) 10/99

17 (17) 12/89

51R (20) 05/00

40A (10) 07/96

26A (26) 07/92

43R (13) 07/97

Clockmeets spec

watch listdead

unusedin use

Wheelfunctionalwatch listdead

41R (14) 11/00

44R (28) 07/00

27A (27) 09/92 35A (05) 08/93 37A (07) 05/93 34A (04) 10/93 54R (18) 01/01

32A (01) 11/92

15 (15) 10/90 29A (29) 12/92

45R (21) 03/03

6

47R (22) 12/03

31A (31) 03/93

30A (30) 9/96

B

60R (23) 06/04

GPS National Policy Review Constellation Status Modernization program New civil signals US-EC GPS-Galileo agreement Considerations for the Future Summary

Block IIA/IIR Block IIIBlock IIR-M, IIF

III: IIF capabilities &• Improved civil signal (L1C)• Increased accuracy (4.8-1.2m) • Navigation surety

Increased A/J power (+20 dB)

IIA / IIR: Basic GPS• C/A civil signal (L1C/A)• Std Service, 16-24m SEP• Precise Service, 16m SEP

• L1 & L2 P(Y) nav

Modernization

IIR-M: IIA/IIR capabilities &• 2nd civil signal (L2C)• New military code• Flex A/J power (+7dB)

IIF: IIR-M capability plus• 3rd civil signal (L5)

GPS modernization balances military and civil needs

GPSCapabilities

Space Segment

Control Segment

1803 04 05 06 07 08 09 10 11 12 13 14 15 16 17 19FY

M-Code

IIR-M / IIF

IIR-M

IIF

GPS III

L5

SAASM

L2C

GPS Enterprise Perspective ScheduleFY05 PB Baseline

GPS III

Flex-Power

Test IOC / FOC

Test IOC FOC

Test IOC FOC

Test IOC

Test IOC FOC

FOC

Test IOC FOC

1st IIRM IIRM-8Dev

1st IIF IIF-10Dev

IIF-16

ATPConcept

III-30KDP B III-18III-8III-21st GPS IIIDev

IIRM IIFDev

SAASM Flex / Civil M-Code

DevTT&C NAV Final GPS III

UserEquipment Contract

AwardDev

RCVR CardReady for Prod LRU I&T

FOCIOCTestJPO Approved Baseline Based on FY05 PBUpdated as of: 23 Aug 04 SMR

Concept Development Production

Bombers / StrikersSAASM

MUE

SAASM UE Vendors Mobility / Tankers /Munitions

IOT&E Comp Bombers / Strikers / C4ISR Mobility / Tankers

IIRM-2

ConceptATP

Baseline Approval

GPS National Policy Review Constellation Status Modernization program New civil signals US-EC GPS-Galileo agreement Considerations for the Future Summary

L2C Second Civil Signal

Benefits of L2C Improves PNT for ~ 50,000 current scientific/commercial dual

frequency users Extends safety-of-life, single-frequency E-911 applications Provides better protection (24 dB) than C/A against code cross

correlation and continuous wave (CW) interference Improved data structure for enhanced data demodulation (5 dB

better than C/A)

L2C codeL2C code

L5 Third Civil Signal

Improves signal structure for enhanced performance Higher power (-154.9 dBW) Wider bandwidth (24 MHz) Longer spreading codes in the navigation message

Aeronautical Radionavigation Services band Co-primary allocation at WRC-2000 (1164-1215MHz)

L5 signal definition in IS-GPS-705

L5 codeL5 code

New L1C Signal Improvements

Tech solutions exist to add a modernized L1 civil signal Implementation will provide C/A code to ensure backward compatibility Assured of 1.5 dB increase in minimum C/A code power to mitigate any

noise floor increase Enables greater civil interoperability with Galileo

L1CL1C

GPS National Policy Review Constellation Status Modernization program New civil signals US-EC GPS-Galileo agreement Considerations for the Future Summary

Galileo and GPS:Interoperability and Compatibility

GPS and Galileo civil signals should be very similar Opportunity for U.S. and Europe to agree on a common

signal structure at L1 with optimum interoperability Same center frequency, same spectral characteristics Enable common civil receiver designs Obtain even better user navigation performance

Baseline Galileo Signals in Agreement Signed June 2004

BOC(15,2.5) PRSBOC(1,1) OS

Galileo signals spectrally separated from M-code signal-- US and Europe achieve compromise

GPS National Policy Review Constellation Status Modernization program New civil signals US-EC GPS-Galileo agreement Considerations for the Future Summary

Considerations for the Future Receiver capabilities

Minimum number of GPS SVs tracked: currently and in the future requires more than 12 in polar regions

IIR-M – first launch in 2005 with new L2C civil signal 18 or more SVs in constellation by 2010 (maybe early as 2009) Current manufacturers with L2C capability: Septentrio and

Trimble – 3rd manufacturer by March 2005 IIF – first launch in 2006 with new L5 civil signal

18 or more SVs in the constellation (2013?) Other GNSS Systems

Galileo deployment – 2008? GLONASS – restored to 24 satellites using modernized SVs?

GPS-III First launch in 2012? May include modernized signal for L1 (L1C)

Summary

Sustaining constellation performance Launching ~3 per year Fielding GPS augmentations such as L-AII

Modernizing by adding new signals and capabilities beginning with first IIR-M1 launch in 2005 and first IIF launch in 2006 New civil and military GPS signals available starting next year Looking ahead with US-EC GPS-Galileo agreement

Planning to execute for the next generation Further enhancements continuing through GPS III GPS III – study contracts awarded in January 04