The Global Positioning System: Serving the World

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The Global Positioning SystemServing the World

• July 19, 2006

Jason Y. Kim, Senior Advisor National Space-Based
Positioning, Navigation, and Timing (PNT)
Coordination Office Washington, D.C., USA
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Overview

• Introduction
• U.S. Policy
• GPS Performance
• Next-Generation GPS
• International Cooperation

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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

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U.S. Augmentations
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International Augmentations
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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
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New Commercial Applications Are Developed Every
Day

• Open pit mining
• Child safety
• Automatic snowplow guidance
• Spacecraft control
• Power grid management
• Wireless mobile applications

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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 NowEmpowering the Future
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Overview

• Introduction
• U.S. Policy
• GPS Performance
• Next-Generation GPS
• International Cooperation

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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

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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

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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

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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
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Overview

• Introduction
• U.S. Policy
• GPS Performance
• Next-Generation GPS
• International Cooperation

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Constellation Status
29 Operational Satellites (Baseline
Constellation 24)

• 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

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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
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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.
• lt3 m vertical accuracy with 6 second time to
  alarm for aviation

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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
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Overview

• Introduction
• U.S. Policy
• GPS Performance
• Next-Generation GPS
• International Cooperation

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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

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Evolution of GPS Performance
100 m or better

• 1990s
• L1 C/A Signal
• Selective Availability On

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Evolution of GPS Performance
36 m or better

• TODAY
• L1 C/A Signal
• Selective Availability Off
• Improved Orbit Information
• L2C Signal (1 satellite)

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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

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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

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GPS Modernization Program
Increasing System Capabilities w Increasing
Defense / Civil Benefit
Block IIA/IIR
Block III
Block IIR-M, IIF

• Backward compatibility
• 4th civil signal (L1C)
• Increased accuracy
• Increased anti-jam power
• Assured availability
• Navigation surety
• Controlled integrity
• Increased security
• System survivability

• 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

• Basic GPS
• Standard Service
• Single frequency (L1)
• Coarse acquisition (C/A) code navigation
• Precise Service
• Y-Code (L1Y L2Y)
• Y-Code navigation

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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
Increases accuracyfor consumers
Supports miniaturization, possible indoor use
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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

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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
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Overview

• Introduction
• U.S. Policy
• GPS Performance
• Next-Generation GPS
• International Cooperation

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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

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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)
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Japan

• Worlds 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

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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
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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 ICAOs 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

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Brazil

• 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

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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
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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

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Muito Obrigado!
PNT.GOV

• National Space-Based PNT Coordination Office6822
  Herbert C. Hoover Building Washington, D.C.
  20230USA
• pnt.office_at_pnt.gov1 [phone]