B. Control Segment
The GPS control segment comprises of a worldwide arrangement of ground amenities that assist in tracking the GPS satellites in the constellation, supervise their communication, execute analysis, and launch guidelines and orders, that facilitate the navigation services.
The master control station (MCS) is situated in Schriever AFB Colorado in North America, seen in Fig.2 [8] and an alternate master station in California.
There are a total of 4 ground antenna’s, 6 Air Force monitor station, 10 NGA monitor station.