| definition |
- The Global Positioning System (GPS) Satellite is a system of satellites developed by the US Department of Defense to provide all-weather round-the-clock navigation capabilities for military ground, sea, and air forces. Since its implementation, GPS has also become an integral asset in numerous civilian applications and industries around the globe, including recreational uses (e.g. boating, aircraft, hiking), corporate vehicle fleet tracking, and surveying. GPS employs 24 spacecraft in 20,200 km circular orbits inclined at 55 degrees. These spacecraft are placed in 6 orbit planes with four operational satellites in each plane. All launches have been successful except for one launch failure in 1981. The full 24-satellite constellation was completed on March 9, 1994. GPS receivers use triangulation of the GPS satellites' navigational signals to determine their location. The satellites provide two different signals that provide different accuracies. Coarse-acquisition (C/A) code is intended for civilian use, and is deliberately degraded. The accuracy using a typical civilian GPS receiver with C/A code is typically about 100 meters. The military's Precision (P) code is not corrupted, and provides positional accuracy to within approximately 20 meters.
[Summary provided by NASA.]
Group: Platform_Details Entry_ID: GPS Group: Platform_Identification Platform_Category: Navigation Platforms Platform_Series_or_Entity: GPS (Global Positioning System) Short_Name: GPS Long_Name: Global Positioning System Satellites End_Group Group: Synonymous_Platform_Names Short_Name: Navstar Short_Name: USA End_Group Group: Platform_Associated_Instruments Short_Name: GPS Short_Name: GPS RECEIVERS End_Group Group: Orbit Orbit_Altitude: 20,200 km Orbit_Type: MEO > Semi-Synchronous > Navigation End_Group Creation_Date: 2007-02-12 Online_Resource: http://msl.jpl.nasa.gov/Programs/gps.html Sample_Image: http://www.nasa.gov/images/content/104002main_sat_nav.jpg Group: Platform_Logistics Primary_Sponsor: U.S. Department of Defense End_Group End_Group
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