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The Global Positioning System: Serving the World. July 19, 2006. Jason Y. Kim, Senior Advisor National Space-Based Positioning, Navigation, and Timing (PNT) Coordination Office Washington, D.C., USA. Overview. Introduction U.S. Policy GPS Performance Next-Generation GPS
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The Global Positioning System:Serving the World July 19, 2006 Jason Y. Kim, Senior Advisor National Space-Based Positioning, Navigation, and Timing (PNT) Coordination Office Washington, D.C., USA
Overview • Introduction • U.S. Policy • GPS Performance • Next-Generation GPS • International Cooperation
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 signals: • Standard (free of direct user fees) • Precise (U.S. and Allied military) • Three segments: • Space • Ground control • User equipment
Nationwide Differential GPS Wide Area Augmentation System Continuously Operating Reference Stations Local Area Augmentation System U.S. Augmentations
Differential GPS Networks Space-Based Augmentation Systems Global Differential GPS System International GNSS Service International Augmentations
Commercial GPS Applications Span A Wide Range of Economic Activities Satellite Operations Power Grid Management Personal Navigation Surveying & Mapping Trucking & Shipping Aviation Communications Network Synchronization Recreation Railroads Fishing & Boating Offshore Drilling
New Commercial Applications Are Developed Every Day • Open pit mining • Child safety • Automatic snowplow guidance • Spacecraft control • Power grid management • Wireless mobile applications
GPS is 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 • Paid for by U.S. taxpayers • Guided at a national level as multi-use asset • Acquired and operated by Air Force on behalf of USG Available Now—Empowering the Future
Overview • Introduction • U.S. Policy • GPS Performance • Next-Generation GPS • International Cooperation
U.S. Policy History • 1983: President Reagan offers free civilian access to GPS • 1996: GPS declared a dual-use system under joint civil/military management • 1997: Congress passes law requiring civil GPS to be provided free of direct user fees • 2004: President Bush issues new U.S. policy on space-based PNT
Space-Based PNT Policy Objectives • Provide civil GPS and augmentations free of direct user fees on a continuous, worldwide basis • Provide open, free access to information needed to use civil GPS and augmentations • Improve performance of GPS and augmentations • Meet or exceed that of international systems • Improve resistance to interference for civil, commercial, homeland security, and scientific users worldwide • Seek to ensure that international space-based PNT systems are interoperable with civil GPS and augmentations • Or, at a minimum, are compatible
Space-Based PNT Policy Objectives • Provide uninterrupted access to U.S. space-based PNT services for U.S./Allied national security purposes • Improve capabilities to deny hostile use of PNT without unduly disrupting civil and commercial access • Maintain GPS as a component of multiple sectors of the U.S. Critical Infrastructure • Plan for backup capabilities and services
Organizational Structure 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
Overview • Introduction • U.S. Policy • GPS Performance • Next-Generation GPS • International Cooperation
Constellation Status • 16 Block II/IIA satellites • 12 Block IIR satellites • Modernizing 8 remaining Block IIR satellites • 1 Block IIR-M satellite • Transmitting new second civil signal • Continuously assessing constellation health to determine launch need • Next launch: September 2006 29 Operational Satellites (Baseline Constellation: 24)
Civil GPS Performance Standards U.S. commitments to civil GPS performance are documented in the 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
. Improving GPS Performance with Augmentations Augmentations enhance GPS accuracy, monitor integrity • Sub-centimeter accuracy for geodesy, geology, etc. • 2-5 cm accuracy for real-time positioning, surveying, etc. • <3 m vertical accuracy with 6 second time to alarm for aviation
GPS Performance with WAAS U.S. Federal Aviation Administration developed the Wide Area Augmentation System (WAAS) to provide necessary accuracy, integrity, and availability to support flight operations during 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. Augmented GPS fulfills rigorous user needs today
Overview • Introduction • U.S. Policy • GPS Performance • Next-Generation GPS • International Cooperation
Benefits of Next-Generation GPS • For civil users: • Higher standalone accuracy • Robustness against interference • Improved indoor, mobile, and urban use • Interoperability with other GNSS constellations • For military: Enhances navigation warfare • For all users: • System-wide improvements in accuracy, availability, integrity, and reliability • Backward compatibility • Maintains international competitiveness
Evolution of GPS Performance 100 m or better 1990’s • L1 C/A Signal • Selective Availability On
Evolution of GPS Performance 36 m or better TODAY • L1 C/A Signal • Selective Availability Off • Improved Orbit Information • L2C Signal (1 satellite)
Evolution of GPS Performance Improved resistance to interference Increased range for RTK applications 1-3 m NEXT GENERATION • L1 C/A Signal (legacy users) • Selective Availability Off • Improved Orbit Information • L1C, L2C, L5 Signals
Evolution of GPS Performance Improved resistance to interference Improved satellite availability Increased range for RTK applications ~1 m? NEXT GENERATION + COOPERATION • L1 C/A Signal (legacy users) • Selective Availability Off • Improved Orbit Information • L1C, L2C, L5 Signals • GNSS Interoperability
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 • Navigation surety • Controlled integrity • Increased security • System survivability
Second Civil Signal • Designed to meet commercial needs • Freely available since Dec 2005 • Currently on 1 satellite • Will be on all future satellites • Expected to generate over $5 billion in user productivity benefits Benefits existing professional receivers Supports miniaturization, possible indoor use Increases accuracyfor consumers
Third Civil Signal • Designed to meet demanding requirements for transport safety • May also enable global, centimeter-level accuracy using new techniques • Opportunity for international interoperability
Fourth Civil Signal • Designed with international partners for interoperability • 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 Under trees Inside cities
Overview • Introduction • U.S. Policy • GPS Performance • Next-Generation GPS • International Cooperation
U.S. GPS Cooperation • Ongoing cooperation with Europe, Japan, Russia • Compatibility and interoperability • National security • Level playing field in global markets • Seeking formal relations with Australia, India, Brazil • Multilateral cooperation • U.N. International Committee on GNSS • ICAO, IMO, NATO
Europe • GPS-Galileo cooperation agreement signed in 2004 • Parties agreed to implement common signal on Galileo and GPS III • Working groups established: • Compatibility & Interoperability • Trade & 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)
Japan • World’s largest consumer of GPS technology • U.S.-Japan cooperation began in 1998 • Quasi-Zenith Satellite System (QZSS) • Regional system to complement, augment GPS over Japan • Will freely broadcast all GPS signals • GPS-QZSS interoperability achieved
Russia • Cooperation started in 2004 • Working groups are pursuing GPS-GLONASS interoperability • Enhanced PNT through combined service • Combined search and rescue capabilities • Currently pursuing formal cooperation agreement GLONASS satellite
Brazil • U.S. cooperating with DECEA on aviation uses of GPS • Brazil Test Bed for WAAS capability • Operational since 2001 • 1 master station, 5 reference stations • Heart of ICAO’s Caribbean and South American Test Bed • Led to discovery of geomagnetic equatorial ionosphere issue for GPS • GNSS Performance Monitoring System • Needed to comply with ICAO regulations • Will utilize Brazil Test Bed and other sites to monitor GNSS signals received in Brazilian airspace
Rio de Janeiro testbed for Ground-Based Augmentation System Galeão and Santos Dumont airports Precision approaches with Hawker aircraft Unique, challenging environment for testing: geomagnetic equator, mountainous terrain, multiple airports, runways near water New CORS site in Fortaleza Cooperation among U.S. National Geodetic Survey, INPE, and two Brazilian universities SIVAM system for Amazon surveillance U.S. firm played major role in its development Brazil
Brazil • U.S. Government is interested in expanding cooperation to broader mutual interests • Civil applications beyond aviation • Free market access, nondiscrimination • International standards • Preliminary discussions held in 2003 • Workshop hosted at AMCHAM São Paulo in 2004 Seeking to continue dialogue with Government of Brazil
Summary • U.S. policy encourages worldwide use of civil GPS and augmentations • GPS performance is better than ever and will continue to improve • Augmentations enable high performance today • New GPS signal now available • Many additional upgrades scheduled • International cooperation is a priority • Compatibility and interoperability are critical • Opportunity for greater U.S.-Brazil partnership
“Muito Obrigado!” National Space-Based PNT Coordination Office6822 Herbert C. Hoover Building Washington, D.C. 20230USA pnt.office@pnt.gov+1 (202) 482-5809 PNT.GOV