TomTom India has provides us with Infographic on working of a GPS Portable Navigation Device (PND). Here is what they have to say:-
GPS Navigation consists of 2 basic elements:
- GPS receiver in your PND
- Satellites in space
24 satellites are circling the Earth in 6 orbital paths. These orbits have been choreographed so that any GPS receiver on earth always gets a signal from at least 4 satellites, at any given point of time.
GPS receiver in your PND has to know 2 things:
- The location of at least 4 satellites above you
- The distance between you and each of those satellites
- GPS receiver picks up signal (transmitting low power radio signals, travelling by ‘line of sight’) from the satellites to work out current location
- Signals pass though clouds, glass and plastic but usually not through solid objects, like buildings
