Global Positioning System (GPS)

Global Positioning System

GPS systems are extremely versatile and can be found in almost any industry sector. They can be used to map forests, help farmers harvest their fields, and navigate airplanes on the ground or in the air. GPS systems are used in military applications and by emergency crews to locate people in need of assistance...or helps...

The Global Positioning System (GPS) is made up of satellites, ground stations, and receivers. GPS is a system. ... Once the receiver calculates its distance from four or more satellites, it knows exactly where you are.

 how GPS works in six steps:

1. GPS works by using a method called "triangulation" or "trilateration".
2. It needs to get a message from at least three, preferably four satellites
3. To "triangulate", a GPS receiver measures the distance between itself and each satellite. It can measure distance because it works out exactly how long it took for each satellite's message to arrive. (distance = time of arrival * speed of light)
4. To measure travel time, GPS needs very accurate timing which it achieves with atomic clocks on board each satellite.
5. Along with distance, the device needs to know exactly where the satellites are in space at any given time. This information is held inside the GPS receiver itself.
6. Finally, because it knows exactly where the satellites are at that instant, by using some very clever mathematics, it can work out where it is on the ground.