The U.S. Space-Based PNT Current Program and Future Trends Anthony Russo Deputy Director April 23, 2008.

The U.S. Space-Based PNT Current Program and Future

Trends

Anthony RussoDeputy Director

April 23, 2008

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Introduction

• During the past decade, GPS has grown into a global utility providing space-based positioning, navigation and timing (PNT) – Consistent, predictable, dependable policy and

performance– Augmentations improve performance

• Like the Internet, GPS is a critical component of the global information infrastructure – Scalable applications enabling broad new capabilities – Innovations in efficiency, safety, environmental

protection, public security and science

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GNSS is Key to Scientific Monitoringof the Earth

To better understand the changes and complex dynamic processes of our home planet

To better understand the changes and complex dynamic processes of our home planet

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• 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

Global Positioning System (GPS)

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GPS Constellation

• 13 Block IIA satellites• 12 Block IIR satellites• 6 Block IIR-M satellite

– Transmitting new second civil signal (L2C)

• Continuously assessing constellation health to determine launch need– 2 Block IIR(M) satellites remaining– Next launch: June 2008

• Global GPS civil service performance commitment met continuously since December 1993

31 Operational Satellites As of 1 Apr 2008 (Baseline Constellation: 24)31 Operational Satellites As of 1 Apr 2008 (Baseline Constellation: 24)

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GroundAntenna

Master Control Station (Schriever AFB)

GPS Operational Control Segment (OCS)

AscensioAscensionn

Diego Diego GarciaGarcia

Cape Cape CanaveralCanaveralHawaiiHawaii

Kwajalein Kwajalein

Schriever Schriever AFB AFB

ColoradoColorado S KoreaS Korea

AustraliaAustralia

BahrainBahrain

S AfricaS Africa

EnglandEngland

ArgentinaArgentina

EcuadorEcuador

TahitiTahiti

USNOUSNO

AlaskaAlaska

MonitorStation

New New ZealanZealandd

Vandenberg Vandenberg AFB AFB

CaliforniaCalifornia

NGA Monitor Station

OCS Monitor Station

Ground Antenna Future Monitor Station

Master Control Station

Backup Master Control Station

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GPS III (Block III)• Increased accuracy • Increased signal

strength• Signal integrity• Search and Rescue• Common Galileo

OS/GPS (L1C)

Legacy (Block IIA/IIR)• Basic GPS• C/A civil signal (L1C/A)• Std Pos. Service• Precise Pos. Service

• L1 & L2 P(Y) nav

Modernized (Block IIR-M)• 2nd civil signal (L2C)• M-Code signals (L1M, L2M)

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

Upgraded (AEP)• IIR-M IIF TT&C• WAGE, AII, LADO• New MCS/AMCS

Legacy• TT&C• L1 & L2 monitoring

Control Systems

User EquipmentLegacy• Man Pack• MAGR, PLGR• RCVR-3A, 3S • OH, UH• FRPA, CRPA

Upgraded• DAGR• CSEL

• GAS-1• MAGR2K• GB-GRAM

Modernized• MUE• MSR

OCX Block 2 C2• L1C

OCX Block 1 (Modernized)• New Architecture• L2C, L5, M-Code• Flex Power

OCX Block 3/4)• Spot Beam • Mission Planning• Near-real Time Command

and Control

All Segment – GPS Modernization

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GPS Modernization – the Future

• Second civil signal “L2C”– Designed to meet commercial needs

•Higher accuracy through ionospheric correction

– Began with GPS Block IIR-M in Sep 2005; 24 satellites: ~2014

• Third civil signal “L5”– Designed to meet demanding requirements for transportation safety-of-life•Uses highly protected Aeronautical Radio Navigation Service (ARNS) band

– Begins with GPS Block IIF– 1st launch: ~2008 (GPS IIR-M Demo); ~2009 (GPS IIF); 24 satellites: ~2016

• Fourth civil signal “L1C”– Designed with international partners for GNSS interoperability– Begins with GPS Block III– First launch: ~2014; 24 satellites: ~2021

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Continuous Performance Improvement

Decreasing range error

PerformanceStandard

Year

Key measures of effectiveness to evaluate GPS services– Accuracy– Bounded inaccuracy– Assured availability– Integrity– Resistance to RF interference/jamming

Accuracy

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WAAS Architecture

38 Reference

Stations

3 Master

Stations

4 Signal Generator

System/ Ground

Earth Stations

2 Geostationary

Satellite Links

2 Operational

Control Centers

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GEO Satellite Improvements

• IOC WAAS (Commissioned system) utilized two Inmarsat satellites – Provided single satellite coverage

over the majority of the U.S.– Inmarsat satellites removed from

operational WAAS July 2007

• Two replacement satellites launched in 2005

• Intelsat (Galaxy XV)– Operational November 2006

(Datalink Only)– Ranging scheduled operational

mid 2008

• Telesat Canada (Anik F1R)– Operational July 2007, for

corrections & ranging

Telesat107W

Intelsat133W

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U.S. Policy History

• 1978: First GPS satellite launched

• 1983: President offered free civilian GPS access to GPS

• 1996: Established joint civil/military GPS management

• 1997: Congress passes law providing civil GPS access free of direct user fees

• 2000: President set Selective Availability to “Zero”

• 2004: President issues U.S. Policy on Space-Based PNT

• 2007: President announces Selective Availability eliminated from future GPS III satellites

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2004 U.S. Space-Based PNT Policy

• No direct user fees for civil GPS services

• Open public signal structures for all civil services– Promotes equal access for user equipment manufacture,

applications development and value-added services

– Encourages open market-driven competition

• Encourage use of GPS time, geodesy and signal standards

• Promote global compatibility and interoperability of GNSS systems with GPS

• Protect the radionavigation spectrum from disruption and interference

• Recognition of national and international security issues and protect against misuse

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2004 U.S. Space-Based PNT Policy

• Recognizes the changing international scene

– Other nations are implementing space-based systems that provide PNT services

• National Executive Committee for Space-Based PNT

– Chaired by Deputy Secretaries of Defense and Transportation

– Membership includes: State, Interior, Agriculture, Commerce, Homeland Security, Joint Chiefs of Staff and NASA

• Established National Coordination Office with staff from each member agency

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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

U.S. Space-Based PNT Structure

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

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Key Executive Committee Activities

• Five-Year National Space-Based PNT Plan– Summarizes EXCOM agency planning for development, acquisition,

sustainment and modernization of U.S. space-based PNT systems

• Interference Detection and Mitigation Plan– Department of Homeland Security coordinating U.S. capabilities to

detect and mitigate sources of interference to GPS and its augmentations

• National PNT Architecture– Provides national PNT framework/investment strategy to help

guide future PNT system-of-systems investment – 2025 timeframe

• International Cooperation and Consultation– Compatibility and interoperability with other foreign systems

Eight meetings since 2006Eight meetings since 2006

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U.S. Objectives with Other GNSS Service Providers

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

– Radio frequency compatibility

– Spectral separation between M code and other signals

• Achieve interoperability – ability of civil U.S. and non-U.S. space-based PNT services operating together to provide better user capabilities than by relying on one service or signal

– Primary focus on the common L1C and L5 signalsPursue through Bi-lateral and Multi-lateral

CooperationPursue through Bi-lateral and Multi-lateral

Cooperation

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International Committee on GNSS (ICG)and Providers Forum

• ICG was established November 2006

– Promote the use of GNSS and its integration into infrastructures, particularly in developing countries and encourage compatibility and interoperability among global and regional systems

– Members include: GNSS providers (U.S., EU, Russia, China, India, Japan), international organizations and associations

– U.S. to host ICG-3 in Pasadena, Dec 2008

• Providers Forum established at ICG-2, Sep 2007– Six providers listed above are members

– Enables focused discussions on compatibility and interoperability

– Consensus reached on the general definitions of compatibility and interoperability - including spectral separation between each system’s authorized service signals and other systems’ signals

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Summary

U.S. Space-based PNT effort progressing well in policy, programs and international outreach

• Implementation of 2004 U.S. Policy proceeding well

• U.S. space-based PNT system performance continue to imimprove into the future

• International cooperation is a top U.S. priority

– Actively engaged in multi-lateral/bi-lateral consultations

• New GNSS applications emergingAs new space-based GNSSs emerge,

compatibility and interoperability is the key to “success for all”

As new space-based GNSSs emerge, compatibility and interoperability is the key

to “success for all”

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Web-based Information

• PNT.gov established to provide a source for information about U.S. Space Based PNT Program including:– U.S. policy, Executive Committee membership,

Advisory Board and frequently asked questions

– Announcements about Selective Availability and offer letter to International Civil Aviation Organization

– Recent public presentations

• GPS.gov established for public information about GPS applications– Available in English, French, Spanish, Arabic and

Chinese

– Brochures also available in hardcopy upon request

– Links to various other Web sites

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Contact Information

Anthony RussoDeputy Director

U.S. National Coordination OfficeSpace-Based Positioning, Navigation and

Timing 1401 Constitution Ave, N.W.

Washington, D.C. 20230-0001

Ph: (202) 482-5809 Fax: (202) 482-4429

[email protected]

This presentation and other GPS information: www.pnt.gov