Almanac

GPS World, Dec, 2004

GPS SATELLITE INFORMATION

United States and Canada

Navigation Information Service (NIS)

Sponsored by the U.S. Coast Guard Navigation Center, this site offers GPS constellation status, scheduled outage updates, user advisories, and almanac data as well as Differential GPS, Loran-C, and Coast Guard Local Notice to Mariners information.

Voice recording for GPS constellation status: (703) 313-5907.

Radio broadcasts: WWV minutes 14 and 15 and WWVH minutes 43 and 44, 2.5 MHZ, 5 MHZ, 10 MHZ, 15 MHZ, and 20 MHZ (this last one is WWV only).

World Wide Web: http://www.navcen.uscg.gov/gps or http://nis-mirror.com.

For further information: Contact the NIS Watchstander, 24 hours a day, at telephone (703) 313-5900, fax (703) 313-5920, or e-mail nisws@navcen.uscg.mil.

Canadian Space Geodesy Forum

This University of New Brunswick service presents daily GPS constellation status reports and ionospheric disturbance warnings, and news and discussion about GPS and other space-based positioning systems by way of electronic mail. Downloadable files are also available.

To subscribe: E-mail the one-line message [sub CANSPACE your_name] to listserv@UNB.CA.

World Wide Web: http://gauss.gge.unb.ca/CANSPACE.html.> For further information: Contact Terry Arsenault or Richard Langley, telephone (506) 453-4698, fax (506) 453-4943, e-mail se@unb.ca.

Natural Resources Canada, Geodetic Survey Division

On-Line Precise Positions, GPS Data, Precise GPS Orbits and Precise GPS Clock Corrections

Natural Resources Canada, Geodetic Survey Division operates the Canadian Active Control System (CACS), a national network of continuously operating GPS tracking stations. Products derived from CACS include GPS observation data, precise GPS orbits, and precise GPS clock corrections. The system supports the positioning requirements of a broad range of users including the most demanding post mission scientific applications to real-time users requiring meter level accuracies related to the Canadian (CSRS) and International Terrestrial Reference Frames (ITRF). An on-line Precise Point Positioning (CSRS-PPP) service allows GPS users from around the world to recover accurate positions from a single GPS receiver by submitting their RINEX observation data via the Internet. GPS-C, a GPS correction service supports national real-time GPS positioning, including the Canada-wide Differential GPS (CDGPS) Service. Information about access to CACS, data availability, and other geodetic products is available 24 hours a day from a free online subscription service

World Wide Web: http://www.geod.nrcan.gc.ca; http://www.cdgps.com.

For further information: Contact Client Services, 615 Booth Street, Ottawa, Ontario, Canada K1A 0E9; telephone (613) 995-4410, fax (613) 995-3215, e-mail information@geod.nrcan.gc.ca, or contact Paul Godin, information services manager, e-mail pgodin@nrcan.gc.ca.

Holloman GPS Website

Operated by the U.S. Air Force, 746th Test Squadron, Holloman Air Force Base, New Mexico, this service provides GPS information such as archived almanac data in SEM3.6 and YUMA formats, and a special almanac detailing the short GPS week, observed range errors as viewed from the GPS Satellite Reference Station at Holloman AFB, constellation status, and user advisories. All information dates back to 1992 and is available 24 hours a day. The site is also a point of contact for the dual-use/technology-transfer initiative for testing commercial GPS receivers.

World Wide Web: http://gpstest.46tg.af.mil/coe/bbs.> Dial in: (505) 679-1525, DSN 349-1525.

For further information: Contact Dennis Cosentino, telephone (505) 679-1787, DSN 349-1787, e-mail bbs-info@46tg.af.mil.

U.S. National Geodetic Survey (NGS)

Precise GPS Orbit Information

Precise orbit information based on tracking data collected from stations of the International GPS Service is available at the following site:

World Wide Web: http://www.ngs.noaa.gov/CORS.> For further information: Contact the NGS/CORS Information Center, e-mail ngs.cors@noaa.gov, or telephone Don Haw, (301) 713-3208, ext. 161.

2nd Space Operations Squadron

The DoD GPS Support Center and the 2nd Space Operations Squadron (2SOPS), U.S. Air Force, maintain World Wide Web pages for military and DoD users only; civilians are referred to the U.S. Coast Guard's Navigation Information Service (see the first listing in this Almanac). The 2nd Space Operations page offers constellation status, scheduled outages, user advisories, almanac data, electronic mail, and downloadable files. The GPS Support Center (GSC) site offers DOP predictions, GPS performance assessments, anomaly impact analysis, GPS FAQs, and a range of other services designed to meet the needs of GPS users in the field.

World Wide Web: GPS Support Center web page providing performance assessment and prediction information: http://www.schriever.af.mil/GpsSupportCenter/index.htm. The Status/Almanac/NANU web page: http://www.schriever.af.mil/GPS/.> For further information: Questions and anomaly reports from civilians and industry: USCG Navigation Center, web site http://www.navcen.uscg.gov/, e-mail nisws@navcen@uscg.mil, phone (703) 313-5900. For DOD-associated activities only, email gps_support@schriever.af.mil.