GNSS (Global Navigation Satellite System) is a satellite system that is used to pinpoint the geographic location of a user's receiver anywhere in the world. Two GNSS systems are currently in operation: the United States' Global Positioning System (GPS) and the Russian Federation's Global Orbiting Navigation Satellite System (GLONASS). A third, Europe's Galileo, is slated to reach full operational capacity in 2008. Each of the GNSS systems employs a constellation of orbiting satellites working in conjunction with a network of ground stations. Satellite-based navigation systems use a version of triangulation to locate the user, through calculations involving information from a number of satellites. Each satellite transmits coded signals at precise intervals. The receiver converts signal information into position, velocity, and time estimates. Using this information, any receiver on or near the earth's surface can calculate the exact position of the transmitting satellite and the distance (from the transmission time delay) between it and the receiver. Coordinating current signal data from four or more satellites enables the receiver to determine its position. The use of GNSS applications bring a strong impact for both economic development. And industry of all nations Market these products and services is growing at 25% per year is expected in 2020, will be operating for navigation receiver for about 3 billion satellite navigation becomes. An important part of everyday life, not just in cars and mobile phones, but also in energy distribution networks or services and banking. And many other fields , the development of these systems in Europe will be achieved. By Galileo GNSS in the European Union. Global Positioning System (GPS)is at present the only one fully operating satellite navigation system. Users can measure their position, velocity and time, in passive, listen-only mode. GPS receivers collect signals from satellites in view. Since the first satellite had been launched in 1978 the GPS begin indispensable in many segments like marine, terrestrial, or aeronautical applications. Furthermore, the ground control network also updates the satellite clock corrections and ephemerides as well as numerous other parameters essential to determining user position, velocity and time. The GPS signal is transmitted from a device (either stand alone or a mobile phone) and the time and location data is sent to the satellite. The GPS tracking information is processed and then sent to a data center for storage. In the case of GPS tracking, the data is sent to our servers and then translated into meaningful and money-saving reports. Data on our servers is stored from the time you begin tracking with us and is never erased. Fleetmatics has data storage centers in both US and UK.