| The Global Positioning System (GPS) is the fully | | | | signals carry information on the location of the |
| functional Global Navigation Satellite System | | | | satellites location and general system health. It is |
| (GNSS) that can determine a location, speed | | | | by the determination of the position and distance |
| direction and time with the utilization of 24 | | | | of minimum three satellites, the receiver comes |
| medium Earth orbit satellites. Developed by the | | | | to the computation of the position using |
| United States Department of Defense, officially | | | | trilateration. |
| baptized Navstar GPS, it is free for civilian | | | | Generally GPS is divided into three major |
| purposes and activities bringing a revolution in the | | | | segments, namely a space segment (SS), a |
| communication sector. Used widely around the | | | | control segment (CS), and a user segment (US). |
| world for navigation aids, GPS is very much useful | | | | The history of GPS takes back to the early |
| for various activities including map-making, land | | | | forties, the period of World War II. But it was the |
| surveying, commerce and scientific uses. It is also | | | | cold war period that brought much technical |
| an effective application tool for various scientific | | | | advancements in the GPS system. The sending of |
| studies on earthquakes, and synchronization of | | | | Sputnik to space by Soviet Union made the U.S |
| telecommunications networks. | | | | scientists to develop a technology that could trace |
| It is by the measuring of distance between itself | | | | the movement of sputnik leading to the advanced |
| and three or more GPS satellites, that a GPS | | | | GPS technology, which later became a common |
| receiver calculates the position. The distance to | | | | factor in the modern communication. Now this |
| each satellite is known by the measuring the time | | | | technology is used in various day to day |
| delay between transmission and reception of each | | | | communication modes like ship navigation, mobile |
| GPS microwave as the signal travels at a speed | | | | phones and air traveling. |
| almost same to the speed of light. Generally | | | | |