NAVSTAR Global Positioning System (GPS)
Print Friendly, PDF & Email


The NAVSTAR Global Positioning System (GPS) is a space-based, Joint-service program led by the Air Force that distributes Positioning, Navigation and Timing (PNT) data to tactical and strategic organizations. The GPS has three segments: A space segment (nominally 24 satellites), a ground control segment, and a user equipment segment consisting of receivers configured for hand-held, ground, aircraft and watercraft applications.

Military GPS receivers utilize the Selective Availability Anti-Spoofing Module (SAASM) to access the Precise Positioning Service signal for enhanced accuracy and signal protection not available to commercial equipment. The two highest density GPS receivers in the Army today are the Defense Advanced GPS Receiver (DAGR) and the Ground-Based GPS Receiver Applications Module (GB-GRAM). Approximately 331,000 DAGR were fielded through 2012 for dismounted use and platform installations. More than 125,000 GB-GRAM have been procured to date through a still-active Army contract to equip a wide array of weapon systems. In addition, the DAGR Distributed Device (D3) will provide a distributed PNT capability to selected platforms
in FY16.


When operated in keyed mode, SAASM-based GPS receivers provide warfighters with enhanced positional accuracy and signal protection.