The global positioning system, or GPS (Global Positioning System: GPS, English:) is the global positioning system surface. On the basis of the calculation of the frequency of the clock signal from the satellites that orbit around the Earth, which know the position. This causes the system to be able to locate the point of the world by a new version of the GPS receiver is able to calculate the speed and direction of the shares with a map to navigate.
The concept for the development of the GPS system. Starting from 1957, when scientists of the United States. Satellite tracking of Soviet sapu tani And I found the event dopploe of radio waves that appear to come from a satellite. They found that if they know the exact location on the surface of the world. You can specify the location of the satellite from the measuring dopploe, and if you know the exact location of the satellites can locate on the surface of the Earth. On the other hand,
The u.s. Navy is experimenting with a satellite navigation system. The name is originally due to expire in 1960 TRANSIT consists of five satellites Sun best satellite used in the GPS system (GPS Block-I) sends up a trial for the first time in 1978 to military use.
When the event occurs after the 1983 Korean Airlines flight 7 South Korea's charmed into the Nan FAH-binphlat of Soviet Union, and was shot in Northwest passengers 269 people died in all. President Ronald Reagan announced that when the GPS system development was completed to allow people to use it.
GPS satellites are satellites which orbit is intermediate (Medium Earth Orbit: MEO) at altitude of approximately 20200 km (10900 12600 miles or nautical miles) from the surface of the Earth. Used to confirm the location by coordinates from at least four satellites are satellites of the world khotronop the Sun for a period of 4-8 hours per round at speed 4 km/sec. The orbit can be individual as per 4 sun angle 6 ranap 55 degrees by the whole system would need to have 24 satellites over the Sun or to be able to confirm the position covers all points on the surface of Earth. At present, there is a GPS satellite Block-II satellite tv back up about 4-6 Sun.