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The National Geodetic Survey (NGS)
computes orbits for the
Global Positioning System (GPS) satellites in the Global Navigation
Satellite
System (GNSS) using 24 hour data segments observed at a global network
of GNSS
receivers and antennas. The global tracking network is coordinated by
the
International GNSS Service (IGS). The current reference frame used in
the
computation is the IGS05 reference frame, a GPS-only realization of the
latest
International Terrestrial Reference Frame (ITRF2005). An informational
summary
file documenting the computation of NGS orbits and containing other
relevant
information about the observed satellites can be viewed by clicking the
"Analysis Strategy Summary" link below or by navigating to http://igscb.jpl.nasa.gov/igscb/center/analysis/noaa.acn.
NGS is currently one of eight IGS Analysis Centers contributing to the IGS precise products. Each day, NGS, and the other Centers, submit their computed daily orbits to the IGS for inclusion in the IGS Rapid Orbit product (igrWWWWD.sp3). Each week, NGS, and the other Centers, submit their final, precise orbits to the IGS for inclusion in the IGS Final Orbit product (igsWWWW7.sp3). This final orbit is considered the international standard and should be used when there is need for precision. The Final Orbit is made available after analysis of a full GPS week is complete. For example, Sunday through Saturday's orbits will be made available between 10 and 14 days after the end of the GPS week.
In addition to the Final and Rapid orbit products, the IGS supplies the Ultra Rapid Orbit, which is available every 6 hours.
National Geodetic Survey's Continuously
Operating
Reference Stations (CORS)
Related
Geodetic
Resources
Transform between height systems with GEOID99
NOAA's Forecast Systems Lab (GPS derived precipitable water vapor)
U.S. Coast Guard's Navigation Center
U.S. Naval Observatory's GPS Data & Information
Univ. of California's
Scripps Orbit and
Permanent Array Center
Southern California
Integrated GPS Network
Goddard Space Flight Center's Crustal Dynamics Data Information System
Canadian Active Control System
International Earth Rotation Service (IERS)
University NAVSTAR Consortium (UNAVCO)
Geography and Environment Gateway (GEsource)
Physical Sciences Information Gateway (PSIgate)
Orbiteers
Bill
Kass
Bob
Dulaney
Jake Griffiths
Last updated by jake.griffiths on Thursday, 29-Nov-2007 12:03:13 EST |
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