2.There are three parts to the Satellite Navigation System. The first part is the receiver. You can hold it in your hand, or have it fixed into your car, plane, etc. The second part is a group of satellites orbiting the Earth. The satellites. Carry atomic clocks and transmit radio signals. The receiver contacts at least four of the satellites. It measures the distance from each satellite, using the radio waves and the times. The receiver then calculates its exact position. The third part of the system is a network of ground stations. They are located all over the world. They control the satellites and make sure they are working well.