|GPS is a world-wide, space-based navigation system, operated by the U.S. Air Force, that consists of a constellation of 24 satellites. They are constantly monitored by military base-stations. It was first developed for use by the military but is now in use by the civilian population in many different areas. This system provides the military and civilians with accurate information about their position, speed and time anywhere in the world, whatever the weather conditions. Position can be calculated to the meter, and with very advanced systems, to the centimeter.
GPS receivers are now available to most everybody, as technology has been able to reduce them in size to fit amongst other things, cars, boats, farm machinery and even laptop computers.
There is a misperception that GPS is purely a tracking system. This is not so. While there are agencies, such as rental companies, who use these devices to keep track of their vehicles, if a handheld receiver is purchased at an electronics store, the buyer need not fear that he is being tracked.