How do sat nav systems work?
Sat nav systems use a global positioning system (GPS) satellite receiver to calculate their position on the Earth’s surface. This is overlaid onto a local road map showing your position to within 10 metres. Sat nav software calculates the ‘best’ route between two points, using average road speed data with other parameters. All sat nav systems give voice instructions for route guidance, for example, ‘Turn left in 300 yards’. Sat navs let you input your destination as a full postcode, or house number, street and town name. If you don’t know the house number, the sat nav will take you to the postcode or the street so you can be reasonably precise. The best sat nav systems have clear screens with clear visual and audio instructions. They’re also easy to set up and programme in a destination. Sat nav systems are best seen as co-pilots, offering guidance, leaving you to take decisions. A sat nav can’t make judgements and it won’t drive your car.
