Global Positioning System GPS

In ancient times when we travel from one place to other a "Magnet Compass" can be used in ships for direction. Chinese Invented first Magnetic Compass in the world that gives directions. Now a days GPS navigation is used in Cars to track the location of the vehicles and find the safe route for travelling. GPS system can also be used in roads and building construction.

How does it works?

There is a GPS satellite in space. Satellite transmits the signals of location to earth. These signals are received by GPS devices on earth. There are more than 30 satellites moving in one GPS satellite system. Satellites are 20000 KM away from earth moving around the earth. The speed of satellite is fast than earth. There are 6 orbits having 5 satellites in one orbit but only 4 satellites are functioning one of them is spare or extra satellite. Satellites are giving signals to earth GPS receiver.