U.S. Space-Based Positioning, Navigation, and Timing Policy and Program Update

1. U.S. Space-Based Positioning, Navigation, and Timing Policy and Program Update Briefing to the Fifth Meeting of the GREPECAS ATM/CNS Subgroup Lima, Peru 14 November 2006 Kenneth Alexander, Senior Advisor U.S. National Coordination Office for Space-Based Positioning, Navigation, and Timing (PNT)

2. Overview • Introduction • GPS Constellation & Performance • Modernization Plans • U.S. National Space-Based PNT Policy • International Cooperation • Summary

3. What is Space-Based PNT • GPS is a space-based radio-navigation system • Satellites broadcast precise, synchronized time signals and data allowing users to estimate position, velocity, and time • Augmentations improve performance of space-based PNT systems such as GPS • Space-based positioning, navigation, and timing (PNT) includes: • Global navigation satellite systems (e.g. GPS, GLONASS, Galileo, etc.) and their augmentations

4. Global Positioning System • Baseline 24 satellite constellation in medium earth orbit • Global coverage, 24 hours a day, all weather conditions • Four dimensional positioning worldwide • Satellites broadcast precise time and orbit information on L-band radio frequencies • Two types of signals: • Civil (free of direct user fees) • U.S./Allied military • Three segments: • Space • Ground control • User equipment

5. Nationwide Differential GPS Wide Area Augmentation (SBAS) Continuously Operating Reference Stations Local Area Augmentation (GBAS) U.S. Augmentations

6. Space-Based Augmentation Systems Differential GPS Networks Global Differential GPS System International GNSS Service International Augmentations

7. Commercial GPS Applications Span a Wide Range of Economic Activities Satellite Operations Power Grid Management Financial Transactions Personal Navigation Surveying & Mapping Trucking & Shipping Aviation Communications Network Synchronization Railroads Recreation Fishing & Boating Offshore Drilling

8. New Applications Developed Every Day • Environmental monitoring • Excavation/Open pit mining • Child safety, E-911 and other wireless applications • Automatic snowplow guidance • Spacecraft control

9. GPS: a Global Public Service • Free access to civilian signals • One-way broadcast, like FM radio • Public domain documentation • Anyone can develop user equipment • Worldwide utility providing consistent, predictable, dependable performance • Critical component of global information infrastructure • Owned and operated by the U.S. Government • Acquired and operated by Air Force on behalf of U.S. • Paid for by U.S. taxpayers • Guided at a national level as multi-use asset Available Now—Empowering the Future

10. Overview • Introduction • GPS Constellation & Performance • Modernization Plans • U.S. National Space-Based PNT Policy • International Cooperation • Summary

11. GPS Performance1990s 100 m orbetter • L1 C/A Signal • Selective AvailabilityOn

12. GPS IIR-15(M) 25 Sep 06 2nd Modernized GPS Satellite Recent Launches Providing worldwide position, navigation & timing GPS IIR-12 23 Jun 04 GPS IIR-13 06 Nov 04 GPS IIR-14(M) 25 Sep 05 1st Modernized GPS Satellite Next Launch scheduled for Thursday, 16 November 2006

13. Current Constellation 31 Operational Satellites (with planned 16 Nov launch) (Baseline Constellation: 24) 30 Operational Satellites (Baseline Constellation: 24) • 16 Block II/IIA satellites operational • 12 Block IIR satellites operational • 2 Block IIR-M satellites operational • Transmitting new second civil signal (L2C) • Continuously assessing constellation health to determine launch need • 2nd New IIR-M satellite launched 25 Sep 06 • Next IIR-M launch 16 November 2006 • 5 Additional Block IIR-M satellites • Global GPS civil service performance commitment met continuously since ‘93

14. 13 m (95%) 36m or better (global worst case) GPS Performance Current Commitment (since 2001) 13 m (95%) 36m or better (global worst case) • L1 C/A Signal • Selective Availability Off • Improved Orbit Determination

15. Civil GPS Performance Standards U.S. commitments to civil GPS performance documented in GPS Standard Positioning Service Performance Standard (2001) • In support of the service availability standard, 24 operational satellites must be available on orbit with 0.95 probability (averaged over any day) • At least 21 satellites in the 24 nominal plane/slot positions must be set healthy and transmitting a navigation signal with 0.98 probability (yearly averaged) System accuracy far exceeds current standard

16. Civil GPS Performance Standard Actual Performance - Single Frequency URE - Signal in Space User Range Error Continuously Improving Performance

17. Alaska England USNO Wash, DC Bahrain South Korea Ecuador Australia Tahiti South Africa Argentina New Zealand Ground Control System ExpansionAccuracy Improvement Initiative (AII) South Africa Schriever AFB Vandenberg AFB Cape Canaveral Hawaii Kwajalein Diego Garcia Ascension Master / Backup Control Stations:Provide navigation estimation (ephemeris and clock), control the satellites, control the operations network, and schedule missions GPS / NGA monitor stations: Monitor navigation messages to collect system performance metrics, collect environment data, send data to OCS to calculate accurate satellite uploads Ground antennas:Transmit navigation data / commands and collect telemetry

18. Monitoring Before L-AII GPS users on approximately half of the Earth’s surface (shown in white) see at least one unmonitored GPS satellite 100 % of the time A GPS satellite is considered to be “monitored” if it is seen by at least two GPS tracking stations; the minimum of two stations ensures that an alarm is caused by a problem on the satellite and not at a tracking station. Monitoring enables GPS operators to identify errors in satellite transmissions; further upgrades to GPS are needed to ensure that corrective action can executed with sufficient timeliness.

19. Monitoring After L-AII (2006) No GPS users anywhere on the Earth’s surface ever see an unmonitored GPS satellite A GPS satellite is considered to be “monitored” if it is seen by at least two GPS tracking stations; the minimum of two stations ensures that an alarm is caused by a problem on the satellite and not at a tracking station. Monitoring enables GPS operators to identify errors in satellite transmissions; further upgrades to GPS are needed to ensure that corrective action can executed with sufficient timeliness.

20. Legacy Accuracy Improvement Initiative (L-AII) • All users see a small accuracy improvement • Specialized defense systems see greater improvement • More importantly, all users enjoy improved satellite monitoring • Additional tracking data eliminates monitoring gaps • Without L-AII some satellites were out of view of any tracking station for over two hours at a time • Every satellite now “watched” by at least two tracking stations at all times • Controllers can now see satellite problems sooner • User exposure to erroneous satellite signals reduced

21. Overview • Introduction • GPS Constellation & Performance • Modernization Plans • U.S. National Space-Based PNT Policy • International Cooperation • Summary

22. Why Modernize • System-wide service improvements in: • Accuracy • Availability • Continuity & Reliability • Integrity • Robustness against interference • Multiple frequencies enables user equipment ionospheric error corrections • Interoperability with other GNSS constellations • While maintaining Backward compatibility

23. Benefits existing professional receivers Increases accuracyfor consumers Supports miniaturization, possible indoor use Second Civil Signal (L2C) • Designed to meet commercial needs • Freely available since Dec 2005 • Currently on 2 satellites • Will be on all future satellites • Expected to generate over $5 billion in user productivity benefits

24. Third Civil Signal (L5) • Designed to meet aviation safety requirements • ARNS band • Higher power • Wider bandwidth = 10x gain • Longer spreading codes (10x C/A) • May also enable global, centimeter-level accuracy using new techniques • Opportunity for international interoperability

25. Inside cities Under trees Fourth Civil Signal (L1C) • Designed with international partners for interoperability • Specifically for interoperability with the Galileo Open Service • Modernized civil signal at L1 frequency • Original signal retained for backward compatibility • More robust navigation across a broad range of user applications • Improved performance in challenged tracking environments

26. GPS III • Revised acquisition strategy • Incremental block approach to reduce risk and increase flexibility • Separate contracts for space and ground segments • Next-generation satellite bus accommodates increased power requirements • Provides L2C and L5 full operational capability • In combination with GPS IIR-M and IIF satellites • Delivers L1C for interoperability with Galileo, QZSS and other potential systems • Significant increase in system accuracy • Improved availability of accuracy with integrity

27. Improved resistance to interference 1 - 2 m GPS III Performance Estimated 1.8 m horizontal. & 3.2 m vertical Based on: - Dual frequency - 95% Global Average - SIS URE: 0.25 meters - UEE: 0.8 meters Ref: GPS III System Spec (SS-SYS-800) • L1 C/A Signal (legacy users) • Selective Availability remains Off • Improved Orbit Determination • L1C, L2C, L5, L1C Signals with new user equipment

28. . Improving GPS Performance with Augmentations - Today Augmentations enhance GPS accuracy, monitor integrity. and can improve availability • <3 m Vertical accuracy with <6 sec time to alarm for aviation • 2 cm Accuracy for real-time positioning, surveying, etc. • Sub-centimeter accuracy for geodesy, geology, etc.

29. GPS Performance with WAAS (SBAS) FAA developed Wide Area Augmentation System (WAAS) to provide accuracy, integrity, availability and continuity to support all phases of flight Based on observations from January to March 2006. Results are valid when the Localizer Approach with Vertical Guidance (LPV) service is available. During this time frame, LPV was available 98% to 99% of the time. SBAS fulfills rigorous user needs today

30. Overview • Introduction • GPS Constellation & Performance • Modernization Plans • U.S. National Space-Based PNT Policy • International Cooperation • Summary

31. U.S. Policy History • 1983: President Reagan offered free civilian GPS access • 1996: National GPS policy declared GPS a dual-use system under joint civil/military management • 1997: Congress passes law requiring civil GPS to be provided free of direct user fees • 2000: President Clinton turns off Selective Availability • 2004: President Bush issues Space-Based PNT Policy • Updates policy while retaining • principles in previous policy • Recognizes changing national & • international scene since 1996

32. Growth in International Global Navigation Satellite Systems (GNSS) • Sep 2005 – 2nd civil GPS signal • Dec 2005 –first Galileo test satellite • Dec 2005 –3 GLONASS satellites • 2006 – European EGNOS (non aviation) • 2007 – WAAS LPV 200’ Decision Height • 2007 – Japan MSAS ops and then future QZSS • 2008 – European EGNOS aviation ops (Galileo I) • TBD– Indian GAGAN and then future IRNS • 2011 – European Galileo Phase II • TBD China – Compass Interoperability key to seamless global operations

33. U.S. Policy Goals • Provide uninterrupted availability of positioning, navigation, and timing services • Continue to provide civil services that exceed or are competitive with other civil space-based positioning, navigation, and timing services and augmentation systems • Meet growing national, homeland, economic security, and civil requirements, and scientific and commercial demands • Remain essential components of internationally accepted positioning, navigation, and timing services • Promote U.S. technological leadership in applications involving space-based positioning, navigation, and timing services • Remain the pre-eminent military space-based positioning, navigation, and timing service

34. Defense Transportation NationalSpace-based PNT Executive Committee Co-Chairs: Deputy Secretaries Defense & Transportation AdvisoryBoard Sponsor: NASA CoordinationOffice Host: Commerce National Space-Based PNT Organizational Structure White House State Commerce Homeland Security Joint Chiefs of Staff NASA

35. Key Executive Committee Actions • 5-Year National Space-Based PNT Plan • Plan is in draft and FY08 program assessment is in progress • Interference Detection and Mitigation Plan • Department of Homeland Security coordinating U.S. capabilities to detect and mitigate sources of interference to GPS and its augmentations • National Space-based PNT Architecture • Led by DoD’s National Security Space Office and DOT’s Research and Innovative Technology Administration • In 2006, Executive Committee met four times • Last meeting held October 27

36. U.S. Space-Based PNT Advisory Board • Board will conduct assessments and make recommendations to accomplish policy goals and objectives • As tasked by the Executive Committee • NASA is hosting Advisory Board • Board established and membership being finalized • Includes 6 international members • First meeting projected for February 2007

37. Web-based Information • www.PNT.gov established to disseminate information on the U.S. National Executive Committee • Contains information on Membership, Policy, the Advisory Board, frequently asked questions, and recent public presentations • www.GPS.gov established to disseminate information on GPS applications • Brochure on GPS applications available in hardcopy • Contains additional links to various other websites

38. www.PNT.gov

39. www.GPS.gov

40. Overview • Introduction • GPS Constellation & Performance • Modernization Plans • U.S. National Space-Based PNT Policy • International Cooperation • Summary

41. Provide civil GPS and augmentations free of direct user fees on a continuous, worldwide basis Provide open, free access to information needed to develop equipment Encourage international development of PNT systems based on GPS Improve performance of civil GPS & augmentations to meet or exceed other international systems Seek to ensure international systems are interoperable, or at a minimum, are compatible, with civil GPS and augmentations U.S. National Policy on Space-Based Positioning, Navigation, and Timing

42. U.S. National Policy on Space-Based Positioning, Navigation, and Timing • Address mutual security concerns with international providers to prevent hostile use • Provide uninterrupted access to U.S. space-based PNT services for U.S./allied national security purposes • Improve capabilities to deny hostile use of any space-based PNT services without unduly disrupting civil and commercial access

43. U.S. International Cooperation • U.S. Government has engaged in formal cooperative arrangements with Europe, Japan, and Russia since 1996 • To ensure compatibility (non-interference) and interoperability with foreign systems • To maintain and promote a level playing field in the global market • Additional efforts ongoing with Australia, India, Brazil and others • Multilateral cooperation established through U.N. International Committee on GNSS • As well as ICAO, IMO, and NATO

44. GPS-Galileo Agreement • In 2004, United States and European Community signed agreement on GPS-Galileo cooperation • Recognizing importance of compatibility and interoperability for all parties • Agreed to spectrally separate signals for military, civilian, and public regulated services • Agreed to implement a common, open, civil signal on both Galileo and GPS III, free of direct user fees • Working groups establishedto continue cooperation: • Compatibility and Interoperability • Trade and Commercial Applications • Next-Generation GNSS • Security Issues June 26, 2004, press conference at U.S.-EU Summit in Ireland (U.S. Sec. of State Colin Powell, Irish Foreign Minister Brian Cowen, EU Vice-President Loyola De Palacio)

45. Caribbean and South America • U.S. Government interested in expanding cooperation to broader mutual interests • Civil applications aviation and more • Free market access, nondiscrimination • International standards • Workshop support • WAAS test bed activities Seeking continued dialogue with Governments of Caribbean and South America

46. Multilateral group chartered through United Nations First Meeting: November 2006 Purpose: Promote use of GNSS to improve efficiency and security of transport, search and rescue, geodesy, etc., particularly in developing countries Coordination among GNSS providers to ensure both compatibility and interoperability Assistance to developing countries in use of PNT services Focal point for international information exchange Forum for addressing future user needs International Committee on GNSS

47. GPS/GNSS Measures of Effectiveness • Accuracy • Bounded Inaccuracy • Availability • Continuity • Integrity • Resistance to Interference/Jamming

48. Spectrum Protection • Protect spectrum for GNSS (GPS, Galileo, etc) and other current/future critical systems from interference • Degradation harms wide variety of plans and programs • Ultra Wideband, Mobile Satellite Ventures, etc. • Focus areas: • Equitable spectrum management and coordination • U.S. National Spectrum Management legislation • Galileo cooperation for compatibility and interoperability • Requires vigilance and early action on emerging issues – World Radio Conference 2007 rapidly approaching

49. Managing Backup Capabilities • New GPS and Galileo signals improve interference resistance • However, all GNSS systems are subject to interference • Never totally eliminate threat of interference and other disruptions that can have harmful consequences • Galileo is not robust backup to GPS; nor GPS for Galileo • Adequate independent backup systems and/or procedures must be maintained in the future for critical applications • Must determine the minimum level of backup capability recognizing constrained budgets • Acceptable from safety and economic impact points of view • Consider “fail soft” versus “equivalent” backup capability

50. Evolution of GPS Performance: Cooperation Improved resistance to interference Improved satellite availability ~ 1 m * GPS + Other GNSS Services • L1 C/A Signal (legacy users) • Selective Availability remains Off • Improved Orbit Determination • L1C, L2C, L5/E5, L1C Signals with new user equipment • GNSS Interoperability Maintain Adequate Backups for Critical Applications Improve Interference Detection and Mitigation * cm level with augmentation