GPS overview and purpose

Summary

The Global Positioning System (GPS) is a satellite-based navigation and timing system owned by the United States Space Force and operated by Mission Delta 31. It provides geolocation (latitude, longitude, and altitude) and precise time information to GPS receivers anywhere on or near Earth where signals can be received. GPS does not require users to transmit data; it works independently of telephone or Internet reception, though those services can enhance how GPS information is used. GPS was initiated by the U.S. Department of Defense in 1973, with prototype satellites launched in 1978 and full operational capability achieved in 1993. Although originally intended for military use, GPS became available for civilian use in the 1980s, and its civilian accuracy was improved significantly after Selective Availability was disabled in 2000. Modern GPS accuracy ranges from roughly meters for consumer devices to much higher precision for specialized receivers used in surveying and engineering, and the system continues to be modernized with next-generation satellites and control upgrades.

Key Points

• 1

  GPS provides worldwide positioning and timing using satellite signals, without requiring user transmission.

• 2

  It was developed by the U.S. Department of Defense for military needs and later made available for civilian use with improved accuracy.

• 3

  GPS operates as a multi-segment system (space, control, and user segments) where satellites broadcast signals and receivers compute position and time.