GPS

1. (GPS) works by radio, and transmitted from a satellite that is orbiting NAVSTAR 24 moons around the world twice and placed above the Earth at 20,200 kilometers height can be used to find the location on the surface of the Earth 24 hours a day at every point on the surface of the Earth. Use the navigation from one place to another as needed. Track the movement of people and things to do map. Surveyors work (Surveying), as well as a reference to measure the precise time in the world.

1.1. (Space segment) that is located on the space will consist of 24 satellites, satellite-Moon-Moon, backed by a 21 Act radio transmissions from space (Space Vehicles, SVs) and the other 3 are supplementary operating satellites. The orbit of the satellite to each orbit takes 12 hours per cycle, there will be six orbits each have four satellites orbit orbit are tilted angle 55° and 60° away sunsut orbit in such a manner will result in at least four satellites in the sky every point on the surface, the xxx.Click any time, 24 hours satellite GPS Block I call first series has a total of 10 satellite moons each has a high-precision clock, which is a set of atomic clocks is divided into frequency source, caesium, rubidium and Calatrava 2-2 standard time of the satellite has very high accuracy. Watch it in the calculation of the distance between the satellite tuner to the coordinate values will be calculated.

1.2. (The Control segment) consists of the ground station control system (Operational Control System: OCS) located at various parts of the world have a duty to update the information provided to the satellite. An accurate, up-to-date all the time.

1.2.1. The main control station. Located at the air base in the city of Colorado Springs. La Corona, the domain of the United State, the (Colorado Springs), satellite tracking station 5 of the survey tracked by satellite, located at. Hawaiian Islands (Hawaii) in the Pacific Ocean. Aetsensan Islands (Ascension) Atlantic Ocean Islands of Diego Garcia (Diego Garcia), the India Ocean. Khwacha Islands (Kwajalein), the Philippines and the city of Colorado Springs station transceiver khwacha mimic the three islands. The Islands, Diego Garcia, and aetsensan Islands.

1.3. (User segment) consists of a receiver or a GPS that we use are various sizes can be portable or car or boat in to the aircraft GPS machine, will act to change the signal from the SVs position. The speed and estimated time if I want to know the value of X Y Z (Position) and requires at least four satellites, accuracy depending on position of the watch and the GPS which will probably locate an error less than 3 feet is a watch with accuracy can be measured in seconds, the time spent in 0.000000003 reference for GPS satellite system called GPS time.