U.S. GPS Program Update
andInternational Activities toProtect GNSS Spectrum
CSIS/UTokyo/ICG GNSS Training
Programme
Office of Space Affairs
U.S. Department of State
11 January 2022

PART 1:
U.S. Program Update2GPS Constellation Status
37 Satellites • 29 Set Healthy
Baseline Constellation: 24 Satellites
Quantity

AverageAge (yrs)

OldestGPS IIR

6 (6*)

20.0

24.4

GPS IIR-M

7 (1*)

14.2

16.3

GPS IIF

128.0

11.6

GPS III

4 (1*)

1.7

3.0

Satellite Block*Not set healthy

As of 01 Jan 2022

GPS Signal in Space (SIS) Performance
From 01 Jan 21 to 01 Jan 22

Average URE*

Best Day URE

Worst Day URE

47.3 cm

31.5 cm(20 Apr 21)

70.4 cm(13 Mar 21)*All User Range Errors (UREs) are Root Mean Square values
3GPS Modernization
SV families provide L-Band broadcast to User Segment
GPS IIA/IIR• Basic GPS• Nuclear Detonation
Detection System (NDS)

GPS IIR-M• 2nd Civil Signal (L2C)• New Military Signal• Increased Anti-Jam PowerGPS IIF• 3rd Civil Signal (L5)
• Longer Life
• Better Clocks

GPS III (SV01-10)• Accuracy & Power• Increased Anti-Jam Power• Inherent Signal Integrity• 4th Civil Signal (L1C)• Longer Life
• Better Clocks

GPS IIIF (SV11-32)• Unified S-Band Telemetry,
Tracking & Commanding• Search & Rescue (SAR)
Payload• Laser Retroreflector Array• Redesigned NDS Payload

TT&C of Space Segment assets & distribution of data to user interfaces
Legacy (OCS)• Mainframe System• Command & Control• Signal Monitoring

Architecture Evolution
Plan (AEP)• Distributed Architecture• Increased Signal
Monitoring Coverage• Security• Accuracy

OCX Block 0• GPS III Launch &Checkout System
GPS III Contingency Ops (COps)• GPS III Mission on AEP

OCX Block 1/2• Fly Constellation & GPS III• Begin New Signal Control• Upgraded InformationAssurance

OCX Block 2+• Control all signals• Capability On-Ramps• GPS IIIF Evolution

M-Code Early Use (MCEU)• Update OCS to operationalize
Core M-Code for MGUE
Applies Space and Control Segment data for PNT applications

Continued support to an ever-growing number of applications• Annual Public Interface Control Working Group (ICWG)• Standard Positioning Service (SPS) Performance Standard Updates• Precise Positioning Service (PPS) Enhancements• Sustained commitmentto transparency• Visit GPS.gov for more info

Modernized Civil Signals• L2C (Various commercial applications)• L5 (Safety-of-life, frequency band protected)• L1C (Multi-GNSS interoperability)4Wide Area Augmentation System(WAAS) Current Status• Current WAAS provides high availability
service to aviation user in North America•

Current WAAS LPV Coverage

4,086 Localizer Performance with Vertical Guidance(LPV) approaches in the NAS• Over 1050 LPVs are LPV-200’s which provides CAT I
equivalent instrument approach performance• Preparing WAAS to take advantage of Dual
Frequency service that will be provided by GPS•

To continue high availability of WAAS verticalservice during ionospheric disturbances• GEO Sustainability••

WAAS LPV Coverage March 6, 2016 Iono event

Currently maintaining 3 GEO’s (Anik F1R [CRE],
Eutelsat 117 WB [GEO 5], SES-15 [GEO 6] )Intelsat Galaxy 30 (GEO 7), launched August 2020,
currently being integrated, expect operational in2022

WAAS Modernization Efforts••

Dual Frequency Multi-Constellation (DFMC)
Advanced Receiver Integrity Monitoring (ARAIM)

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WAAS Avionics Equipage Status• Over 144,000 WAAS equipped aircraft in theNAS•

WAAS receivers provided by companies such as:
Garmin, Universal, Rockwell Collins, Honeywell,Avidyne, Innovative Solutions & Support (IS&S),
Thales and Genesys Aerosystem (Chelton)• Since 2006, aircraft equipage rates haveincreased each year
• All classes of aircraft are served in all phasesof
Flight•Recent STC for Boeing 737-600/700/800 avionics• Enabling technology for NextGen programs•

Automatic Dependent Surveillance Broadcast (ADS-B)•Performance Based Navigation (PBN)6

U.S. Space-based PNT Policy(2020 NSP & SPD-7)
Maintain U.S. leadership in the service provision, andresponsible use of GNSS, including GPS and foreign systems•

Ensure compatibility ― ability of U.S. and non-U.S. space-based PNT services to beused separately or together without interfering with each individual service or signal•

Encourage interoperability – ability of civil U.S. and non-U.S. space-based PNT
services to be used together to provide the user better capabilities than would be achievedby relying solely on one service•Promote transparency in civil service provision and enable market access for U.S.
industry•Promote and support the responsible use of GPS as the pre-eminent space-based PNTservice•

Foreign space-based PNT services may be used to complement civil GPS service– Receiver manufacturers should continue to improve security, integrity, and resilience in the face ofgrowing cyber threats•

Encourage foreign development of PNT services and systems based on GPS•

Support international activities to detect, mitigate, and increase resilience toharmful disruption or manipulation of GPS7

National Space-Based PNT
Organizations
DefenseTransportation

WHITE HOUSE

National Security Council / National Space Council /Office of Science and Technology Policy

StateTreasury
Justice
Interior
Agriculture

NATIONALEXECUTIVE COMMITTEEFOR SPACE-BASED PNTCommerce

Executive Steering GroupADVISORY
BOARD
Sponsor: NASA

Co-Chairs: Defense, Transportation

EnergyHomeland Security

NATIONAL
COORDINATION OFFICEODNI

Host: Commerce

Joint Chiefs of Staff
NASA
Civil GPS Service
Interface Committee
Chair: Transportation
Deputy Chair: Coast Guard

GPS International
Working Group
Chair: StateEngineering Forum
Co-Chairs: Defense,Transportation

Ad HocWorking Groups

8Bilateral International Cooperation
Europe• GPS-Galileo Cooperation Agreement signed in 2004
• U.S.-EU Space Dialogue and three Working Groups meet regularlyJapan• Comprehensive Space Dialogue held August 2020
• Technical Working Group discusses GPS and QZSS compatibilityand interoperability

India• U.S.–India Joint statement on GNSS Cooperation – 2007
• Civil Space Joint Working Group (CSJWG) met November 2019

China
• Three Working Groups and GNSS Plenary meeting held May 2018
• Joint Statement of Cooperation on Civil Signal Compatibility andInteroperability – November 20179

Multilateral International
Cooperation
International Committee on GNSS (ICG)• Pursuing a Global Navigation Satellite System-of-Systemsto provide civil GNSS services that benefit users worldwide– Promote the use of GNSS and its integration intoinfrastructures, particularly in developing countries– Encourage compatibility and interoperability among globaland regional systems• U.S. priorities include spectrum protection, systeminteroperability and information dissemination• 15th Meeting held in Vienna, Austria in September 2021
• UAE will host the 16th Meeting in 202210

PART 2:GNSS Spectrum
Protection, IDM and theICG

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What is Spectrum Protection?

• "Protection" is about keeping the spectrum 'clean'• Clean spectrum means keeping the frequencies
near to GNSS free from licenced, unlicensed andillegal transmissions that interfere with GNSS
reception, e.g.
– GNSS jammers– Uncontrolled GNSS repeater installations– Spurious emissions from radio equipment, e.g. motors– Other radio services, e.g. TV broadcasts– Malfunctioning electronic equipment
12Clean Spectrum• Clean spectrum for GNSS minimizes signal errors andmaximizes the performance for GNSS receivers– Better and more reliable positioning and timing– Faster time to first fix– Better tracking performance in challenging environments• Keeping spectrum clean requires technical means todetect when such interference occurs• National regulators usually have the capacity to detect
strong interferers– Direction finding equipment or geolocation techniques– The ITU can also help coordinate such activities when crossborder interference occurs
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GNSS Interference• Strong interferers are relatively easy to detect• However, if weak interferers are far away fromthe detectors, they will not be seen
• The weak interfering signals are still stronger
than GNSS and will have widespread impact onGNSS reception• To find weak interferers (e.g. 'personal' GNSSjammers) requires more specialised local
equipment or a dense detector network• The ICG has been considering this challenge
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ICG and GNSS Spectrum
Protection• ITU is responsible for international spectrum
framework, including the protection of radio services• Actual implementation of this framework is
accomplished by national telecommunication
administrations• National telecommunication administrations workwith relevant industries and stake holders• ICG provides a forum that can facilitate andencourage the protection of GNSS spectrum by its
members and participants in a voluntary, nonbinding way15ICG Working Groups•

Systems, Signals and Services (Co-Chairs: U.S. & Russia)− Focus on compatibility and interoperability, encouraging development ofcomplimentary systems− Exchange information on systems and service provision plans− Includes spectrum protection and IDM•

Enhancement of GNSS Performance, New Services andCapabilities (Co-Chairs: India, European Space Agency, China)− Focus on system enhancements (multipath, integrity, interference, etc.) to meet
future needs•

Capacity Building, Education and Outreach (Chair: UN Office forOuter Space Affairs)− Focus on training/workshops, promoting scientific applications, spaceweather•

Reference Frames, Timing and Applications (Co-Chairs: IAG, IGS& FIG)
− Focus on timing, monitoring and reference station networks
3Addressing Spectrum Protectionand IDM within ICG• Establishment of Compatibility Subgroup in 2011
– Focused on compatibility issues to include spectrum
protection and IDM• Establishment of Interference Detection andMitigation Task Force in 2013
– Objectives include:1) Develop a common set of information to be reported toGNSS civil service centers
2) Establish routine communications among the (providerservice) centers3) Develop guidelines for common capabilities to beconsidered in the development of future national IDM
networks– Nine IDM Workshops held since 201217

9th ICG Workshop on IDM• Workshop held virtually on 24 August 2021
• Agenda included:– Incorporating Resilience into IDM – Department of Homeland Security, UnitedStates– Implementation and Definition of Interference Protection Standards at Space
Segment for the European Space Agency - European Space Agency– Environment-aware GNSS Position Estimation Process Realisation in SoftwareDefined Radio (SDR) - University of Rijeka, Croatia– Air-Ground coordinated RFI detection system in airport - China ResearchInstitute of Radio-wave Propagation– Development of the European GNSS Interference Detection Network - EuropeanUnion Agency for Space Programmes– Characterization of ADS-B Performance under GNSS Interference – Standford
University, U.S.
– Madrid Airport and TMA GNSS RFI Monitoring System (DYLEMA-Madrid) Spanish Ministry of Transport– Interference scenario in S-band: NavIC experience - Indian Space ResearchOrganisation
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ICG Recommendations Related toIDM and Spectrum Protection
Recent Recommendations Adopted by the ICG
2014

Evaluate existing and emerging IDM capabilities and consider
developing, testing and implementing these or similarcapabilities

2014/2017

Crowdsourcing capabilities analysis for IDM

2015/2016/2017

UN regional workshops on GNSS spectrum protection and IDM

2015/2016

Campaign of Protection of RNSS operations – GNSS providers
and GNSS user community member states promote spectrumprotection

2015/2016

UN COPUOS multi-year agenda item focused on National Efforts
to protect RNSS Spectrum, and develop IDM capability

2017

Encourage national regulators to use the protection criteria inrelevant ITU-R Recommendations

2019

Produce a draft booklet on GNSS/RNSS spectrum Protection
based on material used for the ongoing spectrum seminars

1919

Other Related Topics Discussed
within the ICG• Adjacent Band Compatibility• Unintentional Interference– Electromagnetic emissions limits from non-licensedtransmitters• Interference Detection and Geo-Location
Capabilities• Critical Infrastructure

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For Additional Information…

www.gps.gov

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