1. 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 Program and GPS Policies Long-Term Considerations for Networks Larry Hothem Antarctic Remote Observatory Meeting Boulder, CO 19-20 Sept. 2004

2. GPS National Policy Review Constellation Status Modernization program New civil signals US-EC GPS-Galileo agreement Considerations for the Future Summary GNSS Modernization Program and GPS Policies Long-Term Considerations for Networks

3. Agriculture Commerce State Interior NASA Joint Chiefs of Staff Interagency GPS Executive Board (IGEB) DefenseTransportation Established in 1996

4. 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

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

6. Constellation Summary Since 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

7. 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

8. GPS Space and Control Clock and Reaction Wheel Performance Status ( as of 1 Aug 2004) 39A (09) 06/93 25A (25) 02/92 1 2 SLOTSLOT 3 4 5 PLANE ACDEF 2341 SVN (PRN) 2341 Clock* Wheel * II/IIA = Rb, Rb, Cs, Cs IIR = Rb, Rb, Rb Diagonal Line = Unhealthy launch date 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 Clock meets spec watch list dead unused in use Wheel functional watch list dead 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

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

10. 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

11. GPS Capabilities Space Segment Control Segment 1803040506070809101112131415161719FY M-Code IIR-M / IIF IIR-M IIF GPS III L5 SAASM L2C GPS Enterprise Perspective Schedule FY05 PB Baseline GPS III Flex-Power Test IOC / FOC Test IOC FOC Test IOC FOC Test IOC Test IOCFOC Test IOCFOC 1 st IIRMIIRM-8 Dev 1 st IIFIIF-10 Dev IIF-16 ATP Concept III-30KDP BIII-18III-8III-21 st GPS III Dev IIRMIIF Dev SAASM Flex / Civil M-Code Dev TT&CNAVFinal GPS III User Equipment Contract Award Dev RCVR Card Ready for Prod LRU I&T FOCIOC Test JPO Approved Baseline Based on FY05 PB Updated as of: 23 Aug 04 SMR ConceptDevelopment Production Bombers / Strikers SAASM MUE SAASM UE Vendors Mobility / Tankers / Munitions IOT&E Comp Bombers / Strikers / C4ISR Mobility / Tankers IIRM-2 Concept ATP Baseline Approval

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

13. 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 code

14. 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 code

15. 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 L1C

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

17. 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

18. Baseline Galileo Signals in Agreement Signed June 2004 BOC(15,2.5) PRS BOC(1,1) OS Galileo signals spectrally separated from M-code signal -- US and Europe achieve compromise

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

20. 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 – 3 rd 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)

21. 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