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David A. Turner, Deputy Director Office of Space and Advanced Technology Bureau of Oceans, Environment and Science U.S. Department of State U.S. Space-Based.

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Presentation on theme: "David A. Turner, Deputy Director Office of Space and Advanced Technology Bureau of Oceans, Environment and Science U.S. Department of State U.S. Space-Based."— Presentation transcript:

1 David A. Turner, Deputy Director Office of Space and Advanced Technology Bureau of Oceans, Environment and Science U.S. Department of State U.S. Space-Based PNT Policy & International Cooperation April 7, 2008

2 Moscow Satellite Navigation Forum 2008 2 Introduction Like the Internet, GPS has become a critical component of the global information infrastructure –Consistent policy and predictable, dependable performance –Augmentations improve service performance Presentation will address: –U.S. Space-Based Positioning, Navigation, and Timing Policy –Diplomatic efforts to ensure cooperation in providing Global Navigation Satellite Systems and Services

3 Moscow Satellite Navigation Forum 2008 3 U.S. Policy History 1978: First GPS satellite launched 1978: Legislation requires federal radionavigation planning 1983: U.S. President offers free civilian access to GPS 1996: First U.S. GPS Policy. Established GPS as a dual-use system under joint civil/military management 1997: U.S. Congress passes law requiring the GPS standard positioning service to be provided free of direct user fees 2000: U.S. President set Selective Availability to “Zero” 2004: U.S. President issued U.S. Policy on Space-Based PNT 2007: U.S. President announces Selective Availability will no longer be built into modernized GPS III satellites

4 Moscow Satellite Navigation Forum 2008 4 U.S. Policy Principles Provide civil GPS and augmentations free of direct user fees on a continuous, worldwide basis Provide open, free access to information needed to develop equipment Improve performance of civil GPS and augmentations to meet or exceed that of international systems Encourage international development of PNT systems based on GPS Seek to ensure international systems are interoperable with civil GPS and augmentations Address mutual security concerns with international providers to prevent hostile use Outlined in 2004 Presidential Policy on Space- Based Positioning, Navigation, and Timing (PNT)

5 Moscow Satellite Navigation Forum 2008 5 WHITE HOUSE ADVISORY BOARD Sponsor: NASA ADVISORY BOARD Sponsor: NASA NATIONAL EXECUTIVE COMMITTEE FOR SPACE-BASED PNT Executive Steering Group Co-Chairs: Defense, Transportation NATIONAL EXECUTIVE COMMITTEE FOR SPACE-BASED PNT Executive Steering Group Co-Chairs: Defense, Transportation NATIONAL COORDINATION OFFICE Host: Commerce NATIONAL COORDINATION OFFICE Host: Commerce National Space-Based PNT Organization 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 Hoc Working Groups Defense Transportation State Interior Agriculture Commerce Homeland Security Joint Chiefs of Staff NASA

6 Moscow Satellite Navigation Forum 2008 6 2004 U.S. Space-Based PNT Policy ( Excerpts focused on International Relations) Goals: U.S. space-based PNT systems and services remain essential components of internationally accepted PNT services Promote U.S. technological leadership in applications involving space- based PNT services To achieve this, the United States Government shall: Encourage foreign development of PNT services/systems based on GPS –Seek to ensure foreign space-based PNT systems are interoperable with civil GPS and augmentations –At a minimum, ensure compatibility The Secretary of State shall: Promote the use of civil aspects of GPS and its augmentation services and standards with foreign governments and other international organizations Lead negotiations with foreign governments and international organizations regarding civil PNT matters –And, as appropriate in coordination with the SECDEF, military PNT matters

7 Moscow Satellite Navigation Forum 2008 7 Planned GNSS Global Constellations –GPS (24+) –GLONASS (24) –Galileo (27) –Compass (35) Regional Constellations –QZSS (3) –IRNSS (7) Satellite-Based Augmentations –WAAS (3) –MSAS (2) –EGNOS (3) –GAGAN (3) –SDCM (2?)

8 Moscow Satellite Navigation Forum 2008 8 U.S. Objectives in Working with Other GNSS Service Providers Ensure compatibility ― ability of U.S. and non-U.S. space based PNT services to be used 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 to be used together to provide the user better capabilities than would be achieved by relying solely on one service or signal –Primary focus on the common L1C and L5 signals Pursue through Bi-lateral and Multi-lateral Cooperation

9 Moscow Satellite Navigation Forum 2008 9 The Goal of RNSS Civil Interoperability Ideal interoperability allows navigation with one signal each from four different systems with no additional receiver cost or complexity GPS QZS GALILEO GLONASS Interoperable = Better Together than Separate

10 Moscow Satellite Navigation Forum 2008 10 U.S. - Europe Cooperation US-EU agreement signed in 2004 provides solid foundation for cooperation Action is now divided among four working groups set up by the agreement: –Technical, trade, and security issues working groups have met Improved new civil signal (MBOC) adopted in July 2007 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) ‏

11 Moscow Satellite Navigation Forum 2008 11 U.S. - Russian Federation Cooperation U.S.- Russia Joint Statement issued in December 2004 Several very productive technical working group meetings have been held: –Russia WG-1 chair proposed adopting two new civil CDMA signals at L1, L5 to be interoperable with GPS –Still under discussion within the Russian Government Negotiations for a U.S.-Russia Agreement on satellite navigation cooperation have been underway since late 2005

12 Moscow Satellite Navigation Forum 2008 12 U.S. - Japan Cooperation Japan’s status as a world leader in GPS applications and user equipment makes it an important partner Regular policy consultations and technical meetings on GPS cooperation have been held since 1996 and led to the 1998 Clinton-Obuchi Joint Statement Both countries have benefited from the close relationship: –QZSS is designed to be compatible and interoperable with GPS –U.S. working with Japan to set up QZSS monitoring stations in Hawaii and Guam

13 Moscow Satellite Navigation Forum 2008 13 U.S. - India Cooperation Policy and technical consultations on GPS cooperation underway since 2005 –One aim is to ensure interoperability between GPS augmentation system WAAS and India’s planned GAGAN augmentation system based on GPS –Another important topic is ionospheric distortion and solutions U.S.-India Joint Statement on GNSS Cooperation issued in February 2007 in Washington –Bi-lateral meeting held in Bangalore in September 2007 –Technical Meeting focused on GPS-IRNSS compatibility and interoperability held in January 2008

14 Moscow Satellite Navigation Forum 2008 14 U.S. - Australia Cooperation Long history of GPS cooperation between U.S. and Australia U.S.-Australia Joint Delegation Statement on Cooperation in the Civil Use of GPS signed April 19, 2007 –Cooperation expands upon existing efforts to ensure interoperability between GPS and Australia's Ground- based Regional Augmentation System (GRAS) and Ground Based Augmentation System (GBAS) U.S. Coast Guard NAVCEN posts a daily Position Dilution of Precision (PDOP) report in response to Australia’s concerns over planned GPS outages

15 Moscow Satellite Navigation Forum 2008 15 International Committee on Global Navigation Satellite Systems (ICG) ‏ Emerged from 3rd UN Conference on the Exploration and Peaceful Uses of Outer Space July 1999 –Promote the use of GNSS and its integration into infrastructures, particularly in developing countries –Encourage 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

16 Moscow Satellite Navigation Forum 2008 16 2 nd International Committee on Global Navigation Satellite Systems (ICG) ICG-2 held in September in Bangalore, India Established Providers Forum to address common issues Began implementation of the ICG Work Plan within established working groups: –A. Interoperability and compatibility –B. Enhancement of performance of GNSS services –C. Information dissemination, education, outreach & coordination –D. Interaction with monitoring & reference station network organizations U.S. will host the 3rd ICG in December 2008

17 Moscow Satellite Navigation Forum 2008 17 ICG Providers Forum Six space segment providers listed previously are members Purpose: –Focused discussions on compatibility and interoperability, encouraging development of complimentary systems –Exchange of detailed information on systems and service provision plans –Exchange views on ICG work plan and activities Consensus reached at the first meeting on general definitions for compatibility and interoperability –Including spectral separation between each system’s authorized service signals and other systems’ signals http://www.unoosa.org/oosa/en/SAP/gnss/icg.html

18 Moscow Satellite Navigation Forum 2008 Summary International cooperation in the context of National Space-Based PNT Policy principles is a top priority for the U.S. Government U.S. is actively engaged in bi-lateral and multi- lateral cooperation on space-based navigation issues As new space-based GNSS are emerging globally, interoperability is the key to “success for all”

19 Moscow Satellite Navigation Forum 2008 Contact Information David A. Turner Deputy Director Space and Advanced Technology U.S. Department of State OES/SAT, SA-23, Suite 410 Washington, D.C. 20520 202.663.2397 (office) 202.320.1972 (mobile) TurnerDA@state.gov http://www.state.gov/g/oes/sat/ http://pnt.gov/international/

20 BACK-UP

21 Moscow Satellite Navigation Forum 2008 21 ICG Providers Forum Definition of Compatibility Compatibility refers to the ability of space-based positioning, navigation, and timing services to be used separately or together without interfering with each individual service or signal. Radiofrequency compatibility should involve thorough consideration of detailed technical factors, including effects on receiver noise floor and cross-correlation between interfering and desired signals. The International Telecommunications Union (ITU) provides the framework for discussions on radiofrequency compatibility. Compatibility should also involve spectral separation between each system’s authorized service signals and other systems’ signals. Any additional solutions to improve compatibility are encouraged

22 Moscow Satellite Navigation Forum 2008 22 Radio Frequency Compatibility Ensures that signals do not unacceptably interfere with use of other signals Requires thorough consideration of detailed technical factors, including –Effects on receiver noise floor –Crosscorrelation between interfering and desired signals International Telecommunication Union (ITU) provides framework Details are best worked bilaterally between providers

23 Moscow Satellite Navigation Forum 2008 23 ICG Providers Forum Definition of Interoperability Interoperability refers to the ability of open global and regional satellite navigation and timing services to be used together to provide better capabilities at the user level than would be achieved by relying solely on one service or signal. Ideal interoperability allows navigation with signals from at least four different systems with no additional receiver cost or complexity. Common center frequencies are essential to interoperability, and commonality of other signal characteristics is desirable. Multiple constellations broadcasting interoperable open signals will result in improved observed geometry, increasing end user accuracy everywhere and improving service availability in environments where satellite visibility is often obscured. Geodetic reference frames and system time standards should also be considered. Any additional solutions to improve interoperability are encouraged.

24 Moscow Satellite Navigation Forum 2008 24 Main Benefit of Interoperability More Satellites  Better Geometry  Improves: –Satellite coverage  navigate where could not before –Dilution of Precision  accuracy is better everywhere Eliminates DOP holes (with open sky) ‏ –RAIM*  integrity checked everywhere, all the time Eliminates RAIM holes (with open sky) ‏ –Phase ambiguity resolution for survey and machine control applications Geometry * Receiver Autonomous Integrity Monitoring

25 Moscow Satellite Navigation Forum 2008 25 Important for Interoperability Common Center Frequency –Like L5 & E5a Same Antenna Polarization Common Signal Spectrum –Identical receiver time delay with common spectrum Same coherent integration period for acquisition –Usually related to symbol rate –Different symbol rates may require separate search correlators for acquiring signals Essential (cost driver) Desirable (ASIC gate count) Important (no time bias or filter issues)

26 Moscow Satellite Navigation Forum 2008 26 Other Interoperability Factors – System Time System time offset may affect interoperability, depending on the circumstance This is why system time offset parameters will be part of future GPS, Galileo, and QZSS messages –Permits use of only one or two extra satellites Conversely, GPS and GLONASS receivers function well without a time offset message –Receivers compute and remember time offset, to high precision, if 2+3 or more satellites are in view Time offset is a slowly changing solution variable No impact with common differential corrections –From the same reference station or network

27 Moscow Satellite Navigation Forum 2008 27 Other Interoperability Factors – Geodesy ‏ Geodesy differences may affect interoperability, depending on the extent of the differences Much progress in eliminating geodesy offsets –Continuing work is underway Current GNSS geodesy models are so nearly equivalent that most users are not affected –Coordinate system differences are known and can be applied in the receiver software –Also, no impact with common differential corrections

28 Moscow Satellite Navigation Forum 2008 28 L5 1176.45 MHz E5a 1176.45 MHz E5b 1207.14 MHz L2 1227.6 MHz E6 1278.75 MHz L1 1575.42 MHz L1 1575.42 MHz 1242.9375- 1248.625 MHz 1598.0625- 1605.375 MHz GLONASS GALILEO L5 1176.45 MHz L2 1227.6 MHz LEX 1278.75 MHz L1 1575.42 MHz QZSS GPS MMMMMMMMMMMM P(Y)‏ C/A MMMMMMMMMMMM P(Y)‏ C/A GNSS Frequency Bands and Signals Possible future signal L5 1176.45 MHz L2 1227.6 MHz E6 1278.75 MHz L1 1575.42 MHzBeidou/Compass ITU Filings Here Possible future signal SBAS IRNSS Beidou/Compass & IRNSS In S-band


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