Official U.S. government information about the
Global Positioning System (GPS) and related topics
U.S. Statement to the UN Committee on the Peaceful Uses of Outer Space
February 17, 2014
A U.S. government representative delivered the following remarks about GPS during the 51st Session of the Scientific and Technical Subcommittee of the United Nations Committee on the Peaceful Uses of Outer Space (UN COPUOS), held February 10-21, 2014, in Vienna, Austria.
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Statement by Margaret Kieffer, United States Representative, on Agenda Item 9, "Recent Developments in Global Navigation Satellite Systems"
Mr. Chairman, the United States Global Positioning System (GPS) continues to set a high standard of reliability, accuracy, and service to the international community. The constellation continues an expanded 24+3 slot configuration to provide better coverage and availability around the world. Over the past year, the United States pursued diplomatic efforts on a multi-lateral and bi-lateral basis to support compatibility, interoperability, and transparency among current and future space-based positioning, navigation, and timing (PNT) providers.
As of January 2014, the GPS had 31 operational satellites in orbit to ensure a baseline constellation of 24+3 satellites. Seven of the Block IIR-M satellites and four Block IIF satellites are broadcasting a second civil signal called L2C. The IIF satellites are also broadcasting a civil signal at L5, which eventually will be used for safety-of-life applications. Four additional satellites are in residual status and could be re-activated if necessary for constellation sustainment.
The civil GPS performance commitment has been met continuously since December 1993, and we intend to keep this record intact in the future. The entire GPS constellation continues performing at exceptional levels, averaging a user range error of less than one meter (.8 meter). The reliability of the constellation has been enhanced by solid performance from the Block IIR and IIR-M satellites, with solar array and power capacity that far exceeds the specified mean mission duration. The fourth Block IIF satellite was declared operational in June 2013. Up to three new Block IIF satellites could be launched in 2014 to assure modernization and improved performance in the constellation.
As of December 12, 2013, the United States Federal Aviation Administration (FAA) has implemented 3,364 Wide Area Augmentation System (WAAS) Localizer Performance with Vertical guidance (LPV) approach procedures. Currently, there are also 524 Localizer Performance (LP) approach procedures in the United States. These time and fuel saving approaches are implemented in conjunction with the deployment of Satellite-Based Augmentation Systems (SBAS) in other areas of the world. These procedures now provide over two-thirds of the total United States precision approach capability. The WAAS supports three-dimensional navigation throughout most of North America and two-dimensional navigation over much of the western hemisphere. More than 60,000 aircraft and their operators are benefiting from the increased safety and capacity provided by the U.S. implementation of SBAS.
The United States would like to assure the international community that we continue to work diligently to prevent, detect, and mitigate human-caused interference, both unintentional and intentional, to GPS and Global Navigation Satellite Systems (GNSS) users. The 2010 U.S. National Space Policy directs us to "invest in domestic capabilities and support international activities to detect, mitigate, and increase resiliency to harmful interference to GPS...."
We urge continued international support for recommendations from the previous Interference Detection and Mitigation (IDM) workshops held in 2012 and 2013 under International Committee on GNSS (ICG) auspices. In particular, we encourage support for ICG development of educational materials on interference sources and identification of an official monitoring center recognized by the International Telecommunication Union (ITU). The United States encourages other nations and administrations to take appropriate steps to protect GNSS users from interference and improve GNSS robustness to counter interference.
The United States compliments the United Arab Emirates (UAE) on the successful hosting of the Eighth Plenary Meeting of the International Committee on GNSS (ICG) and the meeting of the related Providers' Forum in Dubai, UAE, in November 2013. We once again commend the United Nations Office for Outer Space Affairs (UNOOSA) for its outstanding performance in assisting with the planning and organization of these meetings and for its continued support as the Executive Secretariat for the ICG and Providers' Forum.
The United States was pleased with progress made on the ICG work plan at ICG-8. On the important issue of interference detection and mitigation (IDM), a Task Force was established with a focus on developing a common set of information to be reported to GNSS civil service centers, and plans were made for a Third IDM Workshop to be held in 2014. An Interoperability Task Force was established with a focus on analyzing the results of the April 2013 U.S. hosted Interoperability Workshop and with plans for additional Interoperability Workshops to be held in 2014 (hosted by different GNSS Providers). Finally, an International GNSS Monitoring and Assessment (IGMA) Task Force was established to focus on identifying what service parameters should be monitored, as well as defining the level and methods for carrying out the monitoring. Consensus was also reached that achieving a fully interoperable GNSS Space Service Volume (SSV) would provide significant performance benefits that no single system could provide on its own, with the National Aeronautics and Space Administration (NASA) working to improve GNSS access out to geosynchronous orbit altitudes for all space users.
NASA has also contributed to implementation of laser-retro-reflector arrays on GPS Block III satellites, beginning with GPS-III Space Vehicle 9. Laser ranging to GPS/GNSS satellites will contribute significantly to a more accurate International Terrestrial Reference Frame ITRF), and enable higher levels of positioning and timing for all users. These applications will be enhanced by ongoing and significant U.S. and international investment in Global Geodetic Observing System networks and analysis systems.
In support of these many GNSS-related activities, the United States continues to provide stable financial support to UNOOSA, including support for regional workshops and to the ICG and its Providers' Forum.
In addition to our multilateral efforts on GNSS-related issues, particularly at the ICG, the United States has many productive bi-lateral relationships on satellite navigation issues. Both Russia and the United States intend to work to the maximum extent practicable to pursue compatibility, interoperability, and transparency in the provision of civil satellite-based navigation and timing signals.
During 2013, the United States continued its close cooperation with the European Union on GNSS activities under the 2004 GPS-Galileo Cooperation Agreement. We are pursuing ITU coordination on next generation GPS III signals.
In conclusion, let me reiterate several key policy principles. The United States intends to continue improving GPS's accuracy and availability through improved satellite and clock performance, and modernized satellites. The United States will continue to broadcast GPS signals free of direct user charges. The United States is committed to keeping GPS as a central pillar in an emerging international system of Global Navigation Satellite Systems. As new systems emerge, signal compatibility and interoperability among GNSS, as well as transparency in the provision of open civil services, will be key factors in ensuring that civil users around the world receive the maximum benefit from GNSS applications. Therefore, the United States strongly supports international cooperation among current and future GNSS.
Thank you, Mr. Chairman.
