The Global Positioning System (GPS) is a satellite-based radio navigation system developed and operated by the U.S. Department of Defense. GPS permits land, sea, and airborne users to determine their position, velocity and the time 24 hours a day, in all weather, anywhere in the world. The GPS signals are available to an unlimited number of users simultaneously. The GPS satellites can be used free of charge by anyone.

How does GPS work?

Each GPS satellite transmits signals to equipment on the ground. GPS receivers passively receive satellite signals; they do not transmit. GPS receivers require an unobstructed view of the sky, so they are used only outdoors and they might perform less well within forested areas or near tall buildings. GPS operations depend on a very accurate time reference, which is provided by atomic clocks at the U.S. Naval Observatory. Each GPS satellite has atomic clocks on board.

The Global Positioning System (GPS) uses a network of satellites which let people with GPS receivers pinpoint their location anywhere in the world. TomTom is one of the first companies to make GPS technology available in an easy-to-use form for everyone.

How does TomTom use GPS?
TomTom develops the latest navigation software to bring GPS data and up-to-date map information together in a way that works perfectly with today’s portable devices.

In order to locate your position, your TomTom device (with integrated GPS antenna*) or GPS receiver must have a clear view of the sky. It will not work if you are inside a building or in a tunnel. If the GPS signal is too weak, your TomTom navigation product will not know your current position. It will try to calculate your position based on the road you are on and the speed and direction you are travelling. When the GPS signal is lost, the Driving View is shown in black and white.

* Note: some athermic heat-reflecting windscreens and built-in windscreen heaters block GPS signal reception inside the car. The magnetic, waterproof TomTom GO External Antenna overcomes this and ensures optimal GPS reception, should you place it inside or outside the car.