The predecessor of GPS system is a U.S. radial tire gauge satellite positioning system (Transit), which was developed in 1958 and was formally put into use in 1964
The predecessor of GPS system is a U.S. radial tire gauge satellite positioning system (Transit), which was developed in 1958 and was formally put into use in 1964. This system uses five to six satellites, which composed of starnet pass through the earth 13 times per day, and not provide highly information, in positioning accuracy is not satisfactory. However, radial meter system makes the research and development department of the satellite positioning acquired preliminary experience, auto gps navigation, and verified by the satellite system, the feasibility of positioning for the GPS system development buried the matting. Since the satellite positioning shows the huge advantage in navigation square existence of asymmetric meter system and submarine and ship navigation aspect huge defect. The United States armed forces and civilian departments are in desperate need of a new satellite navigation system. Therefore, the office of naval research experiment room (NRL) put forward the name with Tinmation 12 to 18 satellite 10000km height of the global positioning nets plans, best buy gps, and in 1978, 69 years and 74 years each launched a single test in these satellites, who stars in the preliminary test timing system, this is zips GPS system accurate positioning basis.
The success of pseudo-random code is GPS system achieves the success of an important basis
And the air force has put forward by – B 621 every four to five satellite constellation composed of three or four stroke, the constellation project except one in the satellite USES synchronized track star outside the rest for 24h tilt use cycle track this plan to pseudo-random code (PRN) basis, the satellite location signal transmission of powerful functions, automotive gps reviews, when a signal density less than 1% of environmental noise, can also its detected. The success of pseudo-random code is GPS system achieves the success of a important basis. The navy plans are mainly used to provide low dynamic ship 2 dimensions positioning, air force plans to provide service for high dynamic, however system is too complex. With the development of the two systems will cause a huge fee, and here two plans are designed to provide global positioning in 1973, so the United States defense department will 2 led by the defense department, automotive gps systems, and one of the satellite navigation and positioning joint projects agency (JPO) leadership, will also set up offices in Los Angeles in the air force space. There are numerous members for the agency, including the United States army, Marine corps, navy, ransportation, NATO, the Australian representative and the defense mapping bureau.
