Global positioning system (GPS),
Definition of Global positioning system (GPS):
A worldwide navigation system which allows users to determine their location very precisely by means of receiving equipment that detects timed radio signals from a network of satellites in stable, predictable orbits.
System of 21 US satellites orbiting earth twice a day at an altitude of 10,900 miles to provide satellite ranging. Almost any point on earth can be located by measuring its distance from a group of these satellites. A navigation device in a boat, car, ship, airplane, or mobile phone gets a fix on at least four satellites to measure its precise location (longitude, latitude and, in some cases, altitude and velocity) accurate to within about a meter where the service is supplemented by a ground based transmitter.
Meaning of Global positioning system (GPS) & Global positioning system (GPS) Definition