The average operation life of the satellites is six(6) years and there has been an effort to increase this time to seven and a half or eight (7.5–8) years in the near future. The satellites use solar batteries as their energy source for their high technology systems. They can also adjust their position to their orbit by using special fuelled motors [2,3]. Within the equipment of each satellite, four high precision chronometers are included. A GPS consists of three discrete parts as it is shown in the following Fig. 1. These three parts are: the satellites in orbit, the ground control stations, and the users (satellite receivers found in land, air, sea).