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Navstar Global Positioning System

The Navstar Global Positioning System (GPS) is a constellation of orbiting satellites that provides navigation data to military and civilian users all over the world. The GPS is a space-based radio-positioning and time transfer system. The GPS has three major segments: Space Segment, Control Segment, and User Segment. As a universal positioning system, GPS provides several characteristics not found in other existing equipment which will enhance the conduct of mission operations: Extremely accurate (3-dimensional) position, velocity and time (PVT) determination; a worldwide common grid easily converted to other local datums; passive, all weather operation; real-time and continuous information; and survivability in a hostile environment

GPS provides 24-hour navigation services which include:

GPS satellites orbit the earth every 12 hours emitting continuous navigation signals. With the proper equipment, users can receive these signals to calculate time, location and velocity. The signals are so accurate, time can be figured to within a millionth of a second, velocity within a fraction of a mile per hour and location to within a few feet. Receivers have been developed for use in aircraft, ships and land vehicles as well as for hand carrying.

GPS Global Performance Assessments, October 2004


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Maintained by Steven Aftergood
Created by John Pike
Updated January 17, 2006