U.S. Space-Based Positioning, Navigation, and Timing (PNT) Policy and Modernization

1
U.S. Space-Based Positioning, Navigation, and
Timing (PNT) Policy and Modernization
UNDP/ICAO Seminar Implementation of CNS/ATM
Technology Lima, Peru 27 September 2006 Ken
Alexander, Senior Advisor National Coordination
Office for Space-Based Positioning, Navigation,
and Timing (PNT) Washington, D.C., USA
2
Overview

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

3
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./Allied military)
• Three segments
• Space
• Ground control
• User equipment

4
U.S. Augmentations
5
International Augmentations
Differential GPS Networks
International GNSS Service
6
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
7
New Applications Developed Every Day

• Environmental monitoring
• Excavation/Open pit mining
• Child safety, E-911 and other wireless
  applications
• Automatic snowplow guidance
• Spacecraft control

8
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
  U.S.

Available NowEmpowering the Future
9
Overview

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

10
U.S. Policy History

• 1983 President Reagan offers free civilian
  access to GPS
• 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 Policy on Space-Based
  PNT
• Updates policy while retaining principles in
  previous policy
• Recognizes changing national and international
  scene since 1996

11
2004 Policy Objectives

• Improve performance of GPS and its augmentations
  - improving global services
• Ensure civil services exceed, or are at least
  equivalent to, of other international civil
  space-based PNT services
• Includes robust resistance to interference for
  civil, commercial, homeland security, and
  scientific users worldwide
• Provide space-based civil PNT services free of
  direct user fees on a continuous, worldwide
  basis
• Civil, commercial, homeland security and
  scientific use
• Provide open, free access to information needed
  to use civil GPS and its augmentations

12
2004 Policy Objectives (contd)

• Maintain GPS as a component of multiple sectors
  of U.S. Critical Infrastructure
• Seek to ensure international PNT systems are
  interoperable with GPS and its augmentations
• Or, at a minimum, are compatible
• 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

13
U.S. Space-based PNT Organizational Structure
WHITE HOUSE
Defense
Transportation
NATIONALSPACE-BASED PNT EXECUTIVE
COMMITTEE Co-Chairs Deputy Secretaries
Defense, Transportation
State
ADVISORYBOARD Sponsor NASA
Commerce
Homeland Security
Joint Chiefs of Staff
COORDINATIONOFFICE Host Commerce
NASA
14
National Coordination Office

• Facilitates information sharing, coordination,
  and issue resolution regarding space-based
  positioning, navigation and timing (PNT) across
  Departments of the U.S. Government
• Evaluates plans to modernize the U.S. space-based
  PNT infrastructure, i.e. GPS and its
  augmentations
• Conducts or oversees space-based PNT studies,
  analyses, and projects that have broad U.S.
  Government participation
• Represents the National Executive Committee on
  space-based PNT with Federal, State, and local
  governments
• As well as with the private sector and
  representatives of other governments

15
Executive Committee Actions

• Major efforts
• 5-Year National Space-Based PNT Plan NCO
• Plan is in draft with FY08 program assessment in
  progress
• International Coordination and Cooperation -
  State
• National Space-Based PNT Advisory Board - NASA
• Board established with membership being finalized
• Will conduct studies and provide advice as
  directed by Executive Committee
• First meeting projected late 06

16
Executive Committee Actions (contd)

• Interference Detection and Mitigation Plan - DHS
• Coordinate U.S. capabilities to detect and
  mitigate sources of interference to the GPS and
  its augmentations
• National Space-based PNT Architecture
• Led by DoDs National Security Space Office and
  DOTs Research and Innovative Technology
  Administration
• GPS Performance Standards OSD/NII and AF
• Publishing PPS standard feasibility of SPS
  update
• In 2006, Natl Executive Committee has met 3
  times
• Next meeting 27 Oct 2006

17
Media Relations

• www.PNT.gov established to represent the
  National Executive Committee and Coord Office
• Maintained by National Coordination Office
• Contains information on Policy, ExCom Membership,
  Advisory Board, recent public presentations, and
  frequently asked questions
• Produced brochure on GPS applications
• Being widely distributed copies available upon
  request
• Also available for download on www.GPS.gov
• Additional links to various other websites

18
2004 U.S. Policy Summary

• Demonstrates continued U.S. Government commitment
  to space-based PNT for all
• Provides framework for public/private decision
  makers
• Improves ability to coordinate efforts across
  various agencies of the U.S. Government
• Creates basis for meaningful dialogue between
  service providers and end users
• Promotes common standards for worldwide
  interoperability

19
Overview

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

20
GPS Performance Overview

• Mission success is top priority
• Sustaining worldwide military/civil utility
• Modernizing for civil and military users
• Fielding operational improvements
• Acquisition challenges
• Requirements civil military
• Balancing sustainment modernization
• Cost schedule of modernization efforts
• Synchronizing space, control, and user equipment
  upgrades
• Refined acquisition strategyBack to Basics
  with an incremental block approach

Continuously improving GPS services for
military and civil users worldwide
21
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
GPS IIR-15(M) 25 Sep 06 2nd Modernized GPS
Satellite
22
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 needs
• Not including 25 September 2006 launch
  satellite currently undergoing pre operational
  checkout

23
GPS User Range Error (URE) History
Current Requirement
Actual Performance
Current Objective
URE - Signal in Space Error
24
Legacy Accuracy Improvement Initiative (L-AII)

• All users see a small accuracy improvement
• Specialized defense systems will see greater
  improvement
• More importantly, all users enjoy improved SV
  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

25
SV Monitoring Before L-AII
GPS users on approximately half of the Earths
surface (shown in white) see at least one
unmonitored GPS satellites 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.
26
SV Monitoring After L-AII
No GPS users anywhere on the Earths 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.
27
Evolution of GPS Performance 1990s
100 m or better

• L1 C/A Signal
• Selective Availability On

28
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 standards
29
Evolution of GPS Performance Today
13m (95) 36m or better (worst case)

• L1 C/A Signal
• Selective Availability Off
• Improved Orbit Determination

30
Overview

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

31
GPS Evolution
Space Segment

• Modernized (Block IIR-M)
• 2nd civil signal (L2C)
• M-Code signals (L1M, L2M)
• Flex A/J power (7dB)

• Modernized (Block IIF)
• 3rd civil signal (L5)

• GPS III (Block III)
• Common signal with Galileo (L1C)
• Increased accuracy
• Signal integrity
• Search and Rescue
• Increased A/J powerup to 20dB (Allied use)

• Legacy (Block IIA/IIR)
• Basic GPS
• C/A civil signal (L1C/A)
• Std Pos. Service
• Precise Pos. Service
• L1 L2 P(Y) nav
• NDS

Control Segment

• Upgraded (AEP)
• IIR-M IIF TTC
• WAGE, AII, LADO
• SAASM
• New MCS/AMCS

• Modernized (OCX V1)
• New Architecture
• Enhanced Signal Monitoring

• Legacy
• TTC
• L1 L2 monitoring

• GPS III (OCX V2)
• GPS III TTC
• NAVWAR, GNOC
• L1C, L2C, L5
• Flex Power
• Real-Time C2

32
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

Benefits existing professional receivers
Increases accuracyfor consumers
Supports miniaturization, possible indoor use
33
Third Civil Signal (L5)

• Designed to meet aviation safety requirements
• Higher power
• Wider bandwidth 10x gain
• Longer spreading codes (10x C/A)
• ARNS band
• Opportunity for international interoperability

34
Fourth Civil Signal (L1C)

• 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
35
Evolution of GPS PerformanceNext Generation
Improved resistance to interference
1 to 3 m

• L1 C/A Signal (legacy users)
• Selective Availability remains Off
• Improved Orbit Determination
• L1C, L2C, L5, L1C Signals with new user equipment

36
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 lt6 sec time to alarm
  for aviation

37
GPS Performance with WAAS (SBAS)

• 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
38
Overview

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

39
Global Navigation Satellite Services (GNSS)
Expanding

• Sep 2005 2nd civil GPS signal
• Dec 2005 first Galileo test satellite
• Dec 2005 3 GLONASS satellites
• This year European EGNOS ops (non aviation)
• Japan preparing for MSAS ops in 2007 and QZSS
• India moving forward with GAGAN and IRNS
• China Beidou, Compass

Interoperability key to seamless global operations
40
Evolution of GPS Performance Cooperation
Improved resistance to interference
Improved satellite availability
1 m

• NEXT GENERATION COOPERATION
• L1 C/A Signal (legacy users)
• Selective Availability remains Off
• Improved Orbit Determination
• L1C, L2C, L5, L1C Signals with new user equipment
• GNSS Interoperability

41
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 and others
• Multilateral cooperation
• U.N. International Committee on GNSS
• ICAO, IMO, NATO

42
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)
43
South America and Caribbean Regions

• 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
44
International Committee on GNSS

• Multilateral group chartered through United
  Nations
• First meeting December 2005
• Includes mix of GNSS providers and major user
  group associations

• Promotes use of GNSS to improve efficiency and
  security of transport, search rescue, geodesy,
  etc., particularly in developing countries
• Focal point for international information
  exchange
• Assistance to developing countries in integration
  of PNT services
• Forum for addressing future user needs
• Provider coordination to improve compatibility
  and interoperability among global and regional
  systems

45
Summary

• Implementing new U.S. National Policy
• U.S. policy encourages and promotes worldwide use
  of civil GPS and augmentations
• GPS performance is better than ever and will
  continue to improve
• New GPS signal available Additional improvements
  will continue in the future
• Augmentations enable high performance today
• International cooperation is a priority
• Compatibility and interoperability critical
• Opportunities for greater U.S./Caribbean/South
  American partnerships

46
Contact Information

• Ken Alexander, Senior Advisor
• National Coordination Office for Space-Based PNT
• Herbert C. Hoover Bldg., Rm. 6822
• 1401 Constitution Avenue, NW
• Washington, D.C. 20230 USA
• Ken.Alexander_at_PNT.gov
• Ph 1.202.482.5809
• Fax [phone]
• Presentation and additional policy information
  available at www.PNT.gov
• Additional information available www.GPS.gov