U.S. GPS Program and Policy Update
Ken AlexanderSenior Advisor, National Coordination Office
United States of America
SBAS International Working GroupSaint Petersburg, Russia
June 25, 2013
• U.S. Space-Based PNT Policy
• Global Positioning System Status
• Space System Modernization
• Ground System Modernization
• Affordability
• International Interoperability
Overview
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U.S. Space-Based PNT Organization Structure
WHITE HOUSEWHITE HOUSE
ADVISORY BOARD
Sponsor: NASA
ADVISORY BOARD
Sponsor: NASA
NATIONALEXECUTIVE COMMITTEEFOR SPACE-BASED PNT
Executive Steering Group
Co-Chairs: Defense, Transportation
NATIONALEXECUTIVE COMMITTEEFOR SPACE-BASED PNT
Executive Steering Group
Co-Chairs: Defense, Transportation
NATIONAL COORDINATION OFFICE
Host: Commerce
NATIONAL COORDINATION OFFICE
Host: Commerce
GPS International Working Group
Chair: State
GPS International Working Group
Chair: State
Engineering Forum
Co-Chairs: Defense, Transportation
Engineering Forum
Co-Chairs: Defense, Transportation
Ad HocWorking Groups
Ad HocWorking Groups
DefenseDefense
TransportationTransportation
StateState
InteriorInterior
AgricultureAgriculture
CommerceCommerce
Homeland SecurityHomeland Security
Joint Chiefs of StaffJoint Chiefs of Staff
NASANASA
U.S. National Space Policy 2010
•Provide continuous worldwide access to GPS for peaceful uses, free of direct user charges
•Open, free access to information necessary to use civil GPS and augmentations
•Encourage global compatibility and interoperability with GPS and its augmentations
• Non-U.S. PNT services may be used to augment and strengthen the resiliency of GPS
•Invest in domestic capabilities and support international activities to detect, mitigate and increase resiliency to harmful interference
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U.S. policy on civil GPS access has been stable and consistent for 30 years
U.S. policy on civil GPS access has been stable and consistent for 30 years
PNT Critical Infrastructure Resiliency
• Critical Infrastructure sector dependencies on satellite navigation discussed 2010-2012– Communications (e.g. cellular phone tower
synchronization)– Energy (e.g. power grid synchronization)– Emergency Services (e.g. location)– Transportation Systems (NextGen)http://www.gps.gov/news/2013/05/2013-05-NRE-
public-summary.pdf• February 2013 Presidential Policy Directive
21 and Executive Order 13636 address critical infrastructure
• Ongoing interagency activities will address our Nation’s Critical Infrastructure sectors reliance upon GPS/GNSS for PNT services
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• U.S. Space-Based PNT Policy
• Global Positioning System Status
• Space System Modernization
• Ground System Modernization
• Affordability
• International Interoperability
Overview
Fourth GPS IIF Satellite Launch
Launched May 15, 2013Launched May 15, 2013
Set healthy June 21, 2013Set healthy June 21, 2013
Next launch: Planned for November 2013Next launch: Planned for November 20137
GPS Constellation Status
• “Expandable 24” configuration (27 slots)• 8 Block IIA• 12 Block IIR• 7 Block IIR-M• 4 Block IIF• 4 residuals satellites on orbit• Continuously assessing constellation
health to determine launch need
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31 Satellites Available to UsersAs of Jun 23, 2013
31 Satellites Available to UsersAs of Jun 23, 2013
GPS Civil Commitment
• Global GPS civil service performancecommitments met continuouslysince Dec 1993
• Extensive International andCivil Cooperation– Agreements with 55 international
customers– Over 1 billion civil/commercial users
• GPS embedded in all facets of life– Aviation, Emergency Services,
Timing, Agriculture, Rescue, Automotive, Tracking, Science, Military, Robotics/Control Systems
The GPS TriadThe GPS TriadJoint GPS User Support ServiceJoint GPS User Support Service
USAF GPSOC(military)
USCG NAVCEN(surface)
FAA NOCC(airspace)
Standard Positioning Service (SPS)Signal-in-Space Performance
2008 Standard Positioning Service (SPS) Performance Standard (PS)
(Worst of any SPS SIS URE)
2001 Standard Positioning Service (SPS) Performance Standard (PS)
(RMS over all SPS SIS URE)
Signal-in-Space User Range Error is the difference between a GPS satellite’s navigation data (position and clock) and the truth, projected on the line-of-sight to the user
System accuracy exceeds published standard
System accuracy exceeds published standard
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GPS Operational Control Segment
Vandenberg AFB
California
Alternate Master Control Station
Air Force Monitor Station
Hawaii
Master Control Station
Schriever AFB Colorado
NGA Monitor Station
South Korea
Australia
Bahrain
South Africa
United Kingdom
Argentina
Ecuador
USNO Washington
Alaska
New Zealan
d
Tahiti
AFSCN Remote Tracking Station
Ascension
Diego Garcia
Cape CanaveralFlorida
Kwajalein
Ground Antenna
New Hampshire
Greenland
Guam
• U.S. Space-Based PNT Policy
• Global Positioning System Status
• Space System Modernization
• Ground System Modernization
• Affordability
• International Interoperability
Overview
GPS Modernization Program
Increasing System Capabilities Increasing User Benefit
GPS IIA/IIR GPS IIIGPS IIR-M, IIF• Backward
compatibility• 4th civil signal (L1C)• 4x better User
Range Error than GPS IIF
• Increased availability
• Increased integrity• 15 year design life
GPS IIR-M – Basic GPS plus:
•2nd civil signal (L2C)•M-Code (L1M & L2M)GPS IIF – GPS IIR-Mcapability plus:
•3rd civil signal (L5)•2 Rb + 1 Cs Clocks•12 year design life
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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GPS III Status
• GPS Block III, Satellites 1-8
– Non-Flight Satellite Testbed testing complete
– First 4 satellites in production
• GPS Block III, Satellites 9+
– On track to add search and rescue payload (SAR-GPS) and satellite laser retroreflectors
– Studying options for dual launch and other cost savings
• Second civil signal “L2C”– Designed to meet commercial needs– Available since 2005 without data message– Phased roll-out of CNAV message – Currently 11 SVs in operation
• Fourth civil signal “L1C”– Designed for GNSS
interoperability– Specification developed in
cooperation with industry– Launches with GPS III– Improved tracking
performance
New Civil Signals
• Third civil signal “L5”– Designed to meet transportation safety-of-life
requirements– Uses Aeronautical Radio Navigation Service band– Currently 4 SVs in operation
Urban Canyons
L5 and L1C Provide improved performance in challenged environments
New Civil GPS Signals
Signal Benefits # of Satellites Broadcasting Now
Availability on 24 Satellites
L2C Meets commercial needs for ionospheric correction, higher effective power, etc.
11 ~2018
L5 Meets requirements for safety-of-life transportation; enables triple-frequency positioning techniques
4 ~2021
L1C GNSS interoperability; performance improvements in challenged environments
Will start with GPS III in 2015
~2026
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CNAV Message Testing
• L2C and L5 signals are in development status (i.e. no navigation data provided)
• OCX control segment will enable upload of civil navigation (CNAV) messages for L2C and L5
• Live-sky testing of L2C and L5 with CNAV ongoing (Jun 15 – July 1, 2013)– Public participation encouraged; see
www.gps.gov/pros
• L2C and L5 will eventually replace civil need for semi-codeless access to military P(Y) signals
• All semi-codeless GPS users expected to migrate from military P(Y) signals use by Dec 31, 2020
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Overview
• U.S. Space-Based PNT Policy
• Global Positioning System Status
• Space System Modernization
• Ground System Modernization
• Affordability
• International Interoperability
GPS Modernized Ground System
•Current system Operational Control Segment (OCS)– Now flying GPS IIA/IIR/IIR-M/IIF constellation– Currently provides legacy L1C/A signal
•Next Generation Operational Control System (OCX) – Block 0 (2014)• Supports GPS III launch and checkout– OCX Block I • Operational capability projected in 2016• Provides operational CNAV for L2C and L5• Command & control for GPS IIR/IIR-M/IIF/III
– OCX Block II • Operational capability projected in 2017• Delivers new international signal (L1C) and M-
Code
Monitor Station
Ground Antenna
• U.S. Space-Based PNT Policy
• Global Positioning System Status
• Space System Modernization
• Ground System Modernization
• Affordability
• International Interoperability
Overview
GPS III Dual Launch
• Significantly reduces launch costs – Studies indicate capability can be provided
with minor changes in GPS III SV09+ production line
• Future Size, Weight, Power (SWAP) considerations– Battery & Solar Array Efficiency, Star
Tracker/ IMU, etc…– Allows SV09+ payload considerations– SAR GPS (formerly DASS), Laser Reflectors,
USB• GPS/Launch Directorate Coordination
– Developing final requirements• GPS--specific dual payload adapter• Mission profile
• Reduces launch vehicle schedule needs
NotionalDual Launch
Configuration on Atlas V 551
SV2
SV1
• Smaller GPS Navigation Satellites (NavSats)– Augments GPS III capabilities
• No secondary payloads• PNT-only reduces size, weight and power (SWAP)
– Increased resiliency• Constellation of 24 GPS IIIs & 6 NavSats
– Enables reduced launch costs• Multiple launch capability • Commercial launch capability
– Improves access to space by replenishing the constellation faster
GPS Augmentation Satellite Initiative
SV2
SV1
Pursuing single on-orbit demonstrationPursuing single on-orbit demonstration
• U.S. Space-Based PNT Policy
• Global Positioning System Status
• Space System Modernization
• Ground System Modernization
• Affordability
• International Interoperability
Overview
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International Cooperation
• U.S. goals for GNSS cooperation:– Compatibility and interoperability– Transparency in provision of civil
services– Fair market access– Detecting, mitigating, and
increasing resiliency to harmful interference
• Bilateral relationships– Russia, Europe, Japan, India,
Australia, China
• Multilateral engagement– ICG, APEC, ICAO, IMO, ITU, NATO
International Committee on GNSS (ICG)• Promotes use of GNSS and its integration into
infrastructures, particularly in developing countries
• Encourages compatibility and interoperability among global and regional systems
• Members include: GNSS Providers (U.S., EU, Russia, China, India, Japan), Other Member States of the United Nations, International organizations/associations
• Multi-GNSS Monitoring Subgroup approved Jun 2012– Identify what service parameters should be monitored– Define the level & methods for monitoring
• ICG-8 will be held in November 2013 in Dubai
http://www.icgsecretariat.org25
U.S. - Russia Cooperation
• GPS-GLONASS cooperation statement signed 2004– Compatibility/interoperability of GPS and GLONASS – Interoperability of Search and Rescue (SAR-GPS and
SAR-GLONASS)
• Collaborating toward placement of GLONASS/ SDCM monitoring stations in U.S.
• U.S. is closely monitoring Russian mandates for GLONASS equipage on certain vehicles– Threshold operational requirements are unclear to U.S.
aircraft manufacturers– Technical regulations must comply with WTO
obligations on Technical Barriers to Trade – U.S. recommends technology-neutral, performance-
based navigation (PBN) airspace requirements26
Information to Facilitate GLONASS Use• Provision of a GLONASS Standard Precision Performance
Standard commitments (e.g. comparable to 2008 GPS SPS Performance Standard)– Establishes State commitment to minimum performance levels– Including Satellite and Constellation failure rates
• Updated GLONASS Interface Control Document (ICD) and ICAO Annex 10 SARPS for L1OC and L5OC CDMA signals – Currently ICAO Annex 10 and GLONASS ICD, Edition 5.1, 2008 only
address L1OF (and L2OF) FDMA signals:– GLONASS-K2 L1OC CDMA (BOC 1,1) signals and GLONASS-KM
L5OC CDMA (BOC 4,4) signals centered at 1176.5 MHz facilitate compatibility & interoperability/ complementarity
• Jun 2013, received Russian equivalents (modified for GLONASS) to RTCA MOPS for DO-229C (SBAS) – Looking for DO-253 (LASS/GBAS) / DO-316 equivalents (in English)
• SDCM ICD for regional augmentation of GPS and GLONASS– Need to validate interoperability with DO-229C avionics (including
1575.42 MHz downlink)
GPS Interoperability Initiative
• CNAV Demonstration Summer 2013– Civil Navigation message Type 35
• Allows foreign interoperability of L2C and L5
• Tests GPS/GNSS Time Offset defined protocols– GPS to Galileo– GPS to GLONASS
• Ongoing coordination with other GNSS providers– RF Compatibility
• Prevent interference between GPS and other GNSS
– Interoperability of Open Service (civil) signals• Benefits of multi-GNSS civil
services • GPS PRN code assignment
management and coordination• Use GPS PRN codes
SV2
Summary
•GPS constellation is healthy with 31 usable satellites•Continuously increasing accuracy and capabilities •Modernization of all GPS segments is on track
– Pursuing innovative, cost effective solutions for future GPS•Striving to improve international GNSS cooperation
and compatibility•GPS-GLONASS cooperation ongoing
– Identification of minimum operational capabilities for each phase of flight is essential
– Dual Frequency/Multi-constellation (DFMC) with future GLONASS L1OC and L5OC Standardization avionics can:
• Optimize aviation operational capabilities • Improve GLONASS compatibility and interoperable
•In support of U.S. avionics and aircraft manufacturers, the FAA desires to continue an open dialogue
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For Additional Information…
www.gps.gov
2518 Herbert C. Hoover BuildingWashington, D.C. 20230United States of America
Tel: +1 (202) 482-5809Email: [email protected]
Спасибо
BACKUPFAA Charts
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U.S. Avionics Standards Process• TSOs and ACs are based upon Minimum Operational
Performance Standards (MOPS)• Experience has shown that use of industry consensus
standards is very beneficial– Industry has the greatest technical expertise – Industry consensus promotes fair competition among vendors,
driving cost-effective solutions– Industry consensus reduces risks of divergent industry input during
formal comment period• Industry consensus is developed in standards-making
bodies; for GPS avionics, that is RTCA, Inc.• RTCA, Inc. is a federal advisory committee and complies
with the Federal Advisory Committee Act– Meetings are open to public and announced in Federal Register
• Consensus on Minimum Operational Performance Standards (MOPS) is built through collaboration
• FAA invokes industry consensus in Technical Standard Orders
Current FAA GNSS Orders and Guidance• TSO-C129a (KT-3401 equivalent) is cancelled
– No new approvals or major modifications are permitted– Standard inadequate for Radiofrequency interference environment – Equipment will be phased-out
• Technical Standard Orders for new GPS equipment incorporate more stringent standards and test requirements– TSO-C145c/C146c (GPS augmented by SBAS) evoke RTCA DO-229D– TSO-C161a (GPS augmented by GBAS) evokes RTCA DO-253C– TSO-C196a, (GPS ABAS for supplemental use) evokes RTCA DO-316
• Receivers must detect Selective Availability removal
– More restrictive RF interference mask minimizes RF noise induced performance degradations
• AC20-138D (in final coordination) for airworthiness approval of positioning and navigation aircraft installations – Adds appendix addressing addition of GLONASS “not for credit”
Integrating GLONASS with GPS (AC-138D)
(Slide 1 of 3) • Since there is no FAA TSO, nor RTCA MOPS for
GLONASS or GPS/GLONASS avionics:– Adding GLONASS capability must be accomplished as a
non-TSO function until a GPS/GLONASS MOPS and TSOs are available
– Adding GLONASS capability according to Advisory Circular guidance does not ensure compatibility nor compliance with future requirements
• Some U.S. manufacturers are interested in initiating development of multi-constellation MOPS to include combined GPS/GLONASS and GPS/GLONASS/SBAS avionics
• Annex 10 SARPs do not provide:– Performance and test standards– Satellite/Constellation reliability commitments– Standards for new signal configurations
Integrating GLONASS with GPS (AC-138D) (Slide 2 of 3)
• Manufacturers must ensure that GLONASS is integrated on a non-interference basis
• Addition of GLONASS to GPS, GPS/SBAS, GPS/GBAS avionics must provide an equivalent level of Safety and Performance (i.e., not degrade accuracy, integrity or continuity)
• GPS, GPS/SBAS, and GPS/GBAS equipment must continue to meet the requirements of its approval – Any GLONASS failures, errors, or alerts must not affect
GPS, GPS/SBAS, or GPS/GBAS capability – Additionally, loss of GLONASS function must not affect the
GPS, GPS/SBAS, or GPS/GBAS functions or performance• GLONASS must not be used to supplement or aid
GPS, GPS/SBAS, or GPS/GBAS performance requirements, nor, GPS RAIM prediction requirement
Integrating GLONASS with GPS (AC-138D) (Slide 3 of 3)
• No credit for non-precision approach prediction availability, nor FDE availability for oceanic/remote operations until GLONASS is approved for operational credit
• Adding GLONASS is considered a new and novel major change – The applicant must present a data package detailing
proposed performance, intended function, and limitations
• Expect to upgrade to more stringent requirements of TSO-C196 when adding GLONASS to TSO‑C129a receivers
• No operational credit should be expected for GLONASS use
Evolving Integrity Algorithms• Current RAIM algorithms are based upon:
– Satellite/ constellation failure rates equal to 10-5 and 10-4 respectfully
– Probabilities are based upon 10 satellites in view and not the increased number of satellites available from GPS and GLONASS
– Not designed to mitigate more than one failed satellite at a time
• Multi-constellation RAIM requires essential capability to account for increased (or degraded) satellite and/or constellation performance including failure rates
• The FAA is investigating how Advanced Receiver Autonomous Integrity Monitoring (ARAIM) might support global vertical approach operations using two or more constellations
• Monitoring and other Architecture needs are balanced by the amount of “trust” that can be placed in the core constellation– Reference ARAIM Technical Subgroup Interim Report, Issue
1.0) http://www.gps.gov/policy/cooperation/europe/2013/working-group-c/
Advanced RAIM (Slide 1 of 3)
• Availability of four core constellations by 2020 challenges both aircraft operators/manufacturers and ATC service providers to assess strategic planning for future GNSS use given the potential variations using ABAS (RAIM), SBAS, and GBAS
• SBAS and GBAS fulfil aviation needs using only GPS, but require significant infrastructure investments
• Use of two, or more, constellations improves ABAS availability; however, multi-constellation SBAS and GBAS, as well as use of L5 (2nd civil GPS signal) operational benefits are not clear
Advanced RAIM (Slide 2 of 3)
• On-going ARAIM studies are attempting to evaluate a proper balance between:– RAIM-like approach - high “trust” in performance
of satellites across multiple core constellations allows sparse monitoring and infrequent satellite “health” updates to avionics
– SBAS-like approach – reduced dependence upon “trust” in multi-constellation satellite performance requires dense monitoring networks and frequent updates to avionics
Advanced RAIM (Slide 3 of 3)
• The outlook for ARAIM vertical approach operations using two or more constellations, is favourable, but not yet decisive;
• Less challenging en route and horizontal approach performance requirements might be satisfied by simpler RAIM algorithms, but require further study and validation
• GLONASS provides the opportunity to operationally test potential multi-constellation ARAIM implementations
RAIM ARAIM
Operations Down to RNP 0.1
LPV200
Hazard category Major Hazardous
Signals L1CA L1CA/E1-L5/E5a
Threat model Single fault only
Multiple faults
Nominal error model
GaussianUses bound
broadcast by GPS
Gaussian + nominal/max bias
validated by independent
ground monitoring
Constellations GPS Multi-constellation
RAIM and Advanced RAIM Comparison
Avionics incorporating GLONASS for Credit• The FAA envisions future operational credit for
GLONASS:– After GLONASS system and service provider performance
capabilities are identified (e.g. GPS SPS Performance Standard)
– GLONASS operational support commitments (e.g. publication and distribution of GLONASS international NOTAMs is required prior to any scheduled maintenance and after the onset of any unscheduled outages
– RTCA has completed development of GPS/GLONASS avionics performance standards
• Next generation GNSS Dual-Frequency/Multi-constellation (DFMC) MOPS expected to enable improved performance using GLONASS (or other constellations) in combination with GPS consistent with 2010 Presidential Policy