The Global Positioning Satellite system or GPS for short is a global service for navigation. The official name is the NAVSTAR-GPS but is more commonly known as the GPS navigation system. It is a satellite based service that uses a combination of more than 20 to 30 satellites to precisely locate the position of the receiver. It works through microwave frequency and the system is very precise and can an accurate value to the nearest centimeter because it uses multiple satellites for locating the co ordinates and the average from those is taken as the final result which can lead to a more accurate result.

            This technology was first in use by the US department of defense and was used for army related purpose. And the first successful use of the technology was in the year 1960 by the US navy. The technology works on the basic ground based radio navigation system that was used and invented in the 1940s. The principle rule used by this technology is the Doppler’s effects which states that the frequency will increase as the transmitter comes near and will lower as the transmitter move away from the receiver. This technique was applied to the satellites and the receiver at the earth’s surface.