GPS Receiver

GPS system is composed of United States sophisticated satellite navigation system designed and funded by the Ministry of defence, includes 24 may continue sending location, altitude and time signal satellite, these satellites evenly distributed in six orbits. In General, on the ground of the 5~12 the GPS receiver can receive a satellite signal, but in order to get on the ground position coordinates, you need at least 4 satellite signals, three GPS receivers used to determine latitude, longitude, and altitude, the fourth provides the synchronization time.