PDAs & Sat Nav : The CCL Guide
Sat Nav (short for satellite navigation) uses GPS (global positioning system) to pinpoint exactly the position of the user on a preinstalled map. This is done by the GPS receiver in the users’ device such as a sat nav like tom tom or garmin, PDA or mobile phone. The GPS receiver sends and receives signals from a series of satellites that orbit the globe. The GPS receiver uses the distance between itself and each of the satellites to pinpoint it’s exact location using the exciting mathematical principle of trilateration. Then, depending on the device and the maps installed, the position is displayed on a graphical map.
Tom Tom Sat NavsGarmin Sat Navs
Features to look for
Preinstalled maps
When you buy a sat nav unit, you should make sure that it has the map of where you are traveling installed. Most sat navs sold in the UK have UK maps installed, but if you are traveling further a field you may have to download additional maps, sometimes at extra cost.
Voice Commands
A sat nav with voice commands or spoken instructions can direct you to you destination without taking your eyes off the road. Different units often come with many different voices to choose from, often those of celebrities.
