written by: Haresh Khemani•edited by: Rhonda Callow•updated: 1/29/2009
The GPS navigation system helps you keep the track of your vehicles and find the correct paths to your destination. Let us see the various components of the car GPS navigation system.
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Components of Car GPS Navigation System
The GPS navigation system helps you keep the track of your vehicles and find the correct paths to your destination. There are three main parts of the car GPS tracking system: the constellation of satellites, the receiver and the ground station.
A Constellation of satellites: This is the most important component of the vehicle tracking system. Each of the GPS satellites takes about 12 hours to complete one orbit around the earth. Each satellite is equipped with a highly accurate atomic clock whose accuracy is within three nanoseconds i.e. 0.000000003 second. This makes it possible for it to broadcast signals that are synchronized with those from other satellites.
The signals travel to the earth with the speed of the light. In fact even at this speed the signals take measurable amount of time to reach to the receivers on the surface of the earth. The receiver can also measure the distance of the satellite from the surface of the earth by measuring the difference between the time when the signal is received and the time when it was sent, multiplied by the speed of light. The GPS navigations signals are designed in manner that this measurement is as accurate as possible.
Receivers: The receivers are the devices that receive the signals from the satellite and the ones that are actually used for the tracking purposes. Depending on position of what machine or the person you wish to track you can install the receiver on it. Thus you may hold it in your hand or install it on the vehicle, aircraft, ships, tanks, submarines, cars, and trucks. You can also attach to the body of your child or pet to track its location. At present hundreds of models of receiver are in use.
The receivers detect, decode, and process GPS satellite signals. A typical receiver is of the size of the mobile phone. The newer models are even smaller and can fit into your wrist watch or hand held computer. The basic receiver functions have been miniaturized onto integrated circuits that weigh about one ounce.
Ground Stations: The control segment of the GPS comprises of several ground stations located around the world. Of these the main station is at Colorado. These stations track the navigation signals and send their data back to the master control station. There, the controllers determine any adjustments or updates to the navigation signals needed to maintain precise navigation and update the satellites via the ground antennas.