Global Positioning System Policy and Program Update

1. Global Positioning System Policy and Program Update Inaugural Forum Satellite Positioning Research and Application Center Tokyo, Japan 23 April 2007 James J. Miller, Senior GPS Technologist Space Communications and Navigation Space Operations Mission Directorate

2. Overview • GPS Policy • Objectives and Management • System Improvements & Modernization • Interoperability & International Collaboration • NASA GPS Space Activities • Summary

3. 2004 U.S. PNT Policy Overview (GPS!) • U.S. Space-Based Positioning, Navigation, and Timing (PNT) Policy • Signed on 8 Dec 04; publicly released on 15 Dec 04 • Updated U.S. policy while retaining prior GPS principles • Established a stronger National Space-Based PNT Executive Committee; IGEB disestablished • Chaired by Deputy Secretaries of Defense and Transportation • Created a new National Coordination Office • Created a new Advisory Board from private sector • Enabled new ways tofund future GPS modernization for civil applications

4. U.S. Policy Principles • No direct user fees for civil GPS services • Open public signal structure for all civil services • Promotes equal access for user equipment manufacture, applications development and value-added services • Facilitates open market driven competition • Use of GPS time, geodesy, and signal standards • Global compatibility and interoperability of future systems with GPS • Protect the current radionavigation spectrum from disruption and interference • Recognition of national and international security issues and protecting against misuse

5. New Policy: Goals • Provide uninterrupted availability of PNT services • Meet growing demands in national, homeland, economic security, scientific, and commercial uses • Continue to provide civil PNT services • Ensure they exceed, or are at least equivalent to, those of foreign civil space-based PNT services • U.S. space-based PNT services remain essential components of internationally accepted services

6. National Management of GPS WHITE HOUSE Defense Transportation NATIONALSPACE-BASED PNT EXECUTIVE COMMITTEE Co-Chairs: Defense, Transportation State ADVISORYBOARD Sponsor: NASA Commerce Homeland Security NASA COORDINATIONOFFICE Host: Commerce Joint Chiefs of Staff

7. Overview • GPS Policy • System Improvements & Modernization • GPS Constellation Status • Next Steps for Space and Control Segments • Interoperability & International Collaboration • NASA R&D Activities • Summary

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

9. GPS is a Global “Public Good” • GPS services are like a “super lighthouse” – USG Owned & Operated • Paid for by U.S. taxpayers and provided free to the world • Users are not hailed at port for fee or tax collection • Managed at a national level as a multi-use asset • Acquired and operated by Air Force on behalf of USG • GPS receivers are like AM/FM radios • Whenever, wherever -- without advertising!! • Adding users costs nothing • Tracking its usage is impossible through GPS itself • GPS is not a fee-for-service utility like cable TV • Usage is not metered -- direct cost to user is “zero” • Civil access is open and unconstrained by “locks” or encryption • Public domain documentation • Available on an equal basis to users and industry worldwide • Anyone can develop user equipment “Lighthouses in the sky, serving all mankind” Dr. Ivan A. Getting (1912–2003)

10. GPS Constellation Statusas of 12 Feb 07 • 15 Block IIA satellites operational • 12 Block IIR satellites operational • 3 Block IIR-M satellites operational • 5 additional IIR-M satellites to launch • Since Dec 93, U.S. Government met/exceeded civil GPS service performance commitments • SPS Performance Standard (PS) • U.S. DoD committed to superior GPS service 30 Healthy Satellites Baseline Constellation: 24

11. GPS Monitoring Stations Cape Canaveral Original USAF Sites - 6 NGA sites transmitting to OCS since Aug 2005 - 6 NGA sites transmitting to OCS since Dec 2006 - 5

12. GPS Single Frequency Performance Steady decrease in error due to improvements such as the addition of new monitoring stations, tighter control of clocks, etc. System accuracy far exceeds current standard

13. Overview • GPS Policy • System Improvements & Modernization • GPS Constellation Status • Next Steps for Space and Control Segments • Interoperability & International Collaboration • NASA R&D Activities • Summary

14. GPS Modernization Goals • System-wide improvements in: • Accuracy • Availability • Integrity • Reliability • Robustness against interference • Improved indoor, mobile, and urban use • Interoperability with other GNSS constellations • Backward compatibility

15. GPS Modernization Program Increasing System Capabilities w Increasing Defense / Civil Benefit Block IIA/IIR Block IIR-M, IIF Block III • Basic GPS • Standard Service • Single frequency (L1) • Coarse acquisition (C/A) code navigation • Precise Service • Y-Code (L1Y & L2Y) • Y-Code navigation • IIR-M: IIA/IIR capabilities plus • 2nd civil signal (L2C) • M-Code (L1M & L2M) • IIF: IIR-M capability plus • 3rd civil signal (L5) • Anti-jam flex power • Backward compatibility • 4th civil signal (L1C) • Increased accuracy • Increased anti-jam power • Assured availability • Increased security • System survivability • Search and Rescue

16. Modernized GPS – Civil Signals • Second civil signal (“L2C”) • Designed to meet commercial needs • Higher accuracy through ionospheric correction • Higher effective power and improved data structure reduce interference, speed up signal acquisition, enable miniaturization of receivers, may enable indoor use • Began with GPS Block IIR-M in Sep 2005; 24 satellites: ~2014 • Third civil signal (“L5”) • Designed to meet demanding requirements for transportation safety (safety-of-life) • Uses highly protected Aeronautical Radio Navigation Service (ARNS) band • Begins with GPS Block IIF • First launch: ~2008; 24 satellites: ~2016 • Fourth civil signal (“L1C”) • Designed with international partners to enable GNSS interoperability • Begins with GPS Block III • First launch: ~2013; 24 satellites: ~2021

17. P(Y) C/A L2C M L5 L1C L5 L1 L2 GPS Modernization – Spectrum Block IIA, 1990 previous as of Dec 2005 Block IIR-M, 2005 planned Block IIF, 2008 Block III, 2013 (artist’s concept) ARNS BandRNSS BandARNS Band

18. IIR-15(M) Launch & View From Space 25 September 2006

19. GPS III Acquisition Approach Increment IIIA • Block A Configuration • New L1C Signal • New GPS III SV Platform Plus demo high-speed communication (uplink, downlink & crosslink) Increment IIIB Block A Configuration Plus new capabilities demo Increment IIIC Block A Configuration Block A Configuration Plus new capabilities demo Technology Development / Capability Insertion Program Plan

20. Master Control Station (MCS) Advanced Ground Antenna Ground Antenna (GA) USAF Monitor Station (MS) National Geospatial-Intelligence Agency (NGA) Tracking Station Alternate Master Control Station (AMCS) FAIRBANKS ENGLAND COLORADO SPRINGS SOUTH KOREA USNO WASH D.C. VANDENBERG, AFB CAPE CANAVERAL BAHRAIN Master Control Station HAWAII KWAJALEIN ASCENSION ECUADOR DIEGO GARCIA TAHITI SOUTH AFRICA ARGENTINA NEW ZEALAND OCX Program Description IIR/M IIF III Position, Velocity, Time Data C2 Uplink and Downlink MonitorStations Advanced Ground Antennas Battlespace Awareness AUSTRALIA The next generation GPS control segment (OCX) includes a new infrastructure with functionality that completes modernization capabilities.

21. Overview • GPS Policy • System Improvements & Modernization • GPS Constellation Status • Next Steps for Space and Control Segments • Interoperability & International Collaboration • GPS-QZSS Progress • NASA R&D Activities • Summary

22. GPS/QZSS Agreement – 27 January 2006Unprecedented Compatibility & Interoperability • QZSS designed to work with & enhance civil services of GPS • Availability enhancement • Performance enhancement • GPS & QZSS have established that their signals are RF compatible

23. GPS-QZSS Technical Working Group (TWG) % Time that at Least 1 of 3 QZSS Satellites Is Visible • Civil system for Asia-Pacific region • Enhances civil GPS services • First QZSS launch expected in 2009 • GPS-QZSS technical meetings • Nov 04 in Washington, DC, US • July 05 in Hawaii, US • January 06 in Tokyo, Japan • Aug 06 in Hawaii • Next mtg. in Washington, DC, in May • GPS & QZSS success in designing “common” signals • Five of six QZSS signals use same signal structures, frequencies, spreading code families, data message formats as GPS or SBAS signals • Draft interface specification (IS) for QZSS released in January 2007 • IS-GPS-200, IS-GPS-705, & IS-GPS-800 are baseline documents

24. Overview • GPS Policy • System Improvements & Modernization • GPS Constellation Status • Next Steps for Space and Control Segments • Interoperability & International Collaboration • GPS-QZSS Progress • NASA R&D Activities • GPS to Earth Orbit, and Beyond • Summary

25. GPS and Human Space Flight • Miniaturized Airborne GPS Receiver • (MAGR-S) • Modified DoD receiver to replace TACAN on-board the Space Shuttle • Designed to accept inertial aiding and capable of using PPS • Single-string system (retaining three-string TACAN) installed on OV-103 Discovery and OV-104 Atlantis, three-string system installed on OV-105 Endeavour (TACAN removed) • GPS taken to navigation for the first time on STS-115 / OV-104 Atlantis STS-115 Landing • Space Integrated INS/GPS (SIGI) • Receiver tested on shuttle flights prior to deployment on International Space Station (ISS) • The ISS has an array of 4 antennas on the T1 truss assembly for orbit and attitude determination

26. Navigation with GPS: Space-Based Range • Space-based navigation, GPS, and Space Based Range Safety technologies are key components of the next generation launch and test range architecture • Provides a more cost-effective launch and range safety infrastructure while augmenting range flexibility, safety, and operability • Memorandum signed in November 2006 for GPS Metric Tracking (GPS MT) by January 1, 2011 for all DoD, NASA, and commercial vehicles launched at the Eastern and Western ranges GPS-TDRSS Space-Based Range

27. 47o W 171o W ~18-20o 85o E Augmentation of GPS in Space: GDGPS & TASS • TDRS Augmentation Service for Satellites (TASS) provides Global Differential GPS (GDGPS) corrections via TDRSS satellites • Integrates NASA’s Ground and Space Infrastructures • Provides user navigational data needed to locate the orbit and position of NASA user satellites

28. Navigation with GPS beyond LEO • GPS Terrestrial Service Volume • Up to 3000 km altitude • Many current applications • GPS Space Service Volume (SSV) • 3000 km altitude to GEO • Many emerging space users • Geostationary Satellites • High Earth Orbits (Apogee above GEO altitude) • SSV users share unique GPS signal challenges • Signal availability becomes more limited • GPS first side lobe signals are important • Robust GPS signals in the Space Service Volume needed • NASA GPS Navigator Receiver in development

29. Navigation with GPS beyond Earth Orbit… and on to the Moon • GPS signals effective up to the Earth-Moon 1st Lagrange Point (L1) • 322,000 km from Earth • Approximately 4/5 the distance to the Moon • GPS signals can be tracked to the surface of the Moon, but not usable with current GPS receiver technology

30. Earth-Moon Communications and Navigation Architecture • Options for Communications and/or Navigation: • Earth-based tracking, GPS, Lunar-orbiting communication and navigation satellites with GPS-like signals, Lunar surface beacons and/or Pseudolites • The objective is integrated interplanetary communications, time dissemination, and navigation

31. Summary • Continuing success in GPS sustainment & modernization • New capabilities delivering enhanced performance • Developments on track to enhance space and control segments • Civilian use of GPS, and GPS-derived systems, is already extending well beyond Earth • International participation will make new worldwide GPS applications grow more robust and valuable for generations to come