GLOBAL POSITIONING SYSTEM (NAVSTAR)
GPS - The system consist of about 18 satellites in geosynchronous orbit in three separate planes around the earth. Unlike Transit satnav, the system is continuous, receiving signals from at least 6 separate satellites at anyone time on 1227 MHz and 1575 MHz. The key advantage of the system is that it provides highly accurate latitude, longitude, and altitude coordinates. Whereas the military releases only a certain accuracy for commercial use, GPS will have the capability of accurate fixes measured in feet.
