Positioning system is an interrelated aggregate or device (component) with the goal of determining spatial position. This system can ensure that at least four satellites can be observed at any point on the earth at any time, thus ensuring that satellites can collect the latitude, longitude and height of observation points and realize the functions of navigation, positioning and timing. This technology can be used to guide planes, ships, vehicles and individuals to reach their destinations safely and accurately along selected routes.
Historical development:
Global Positioning System (GPS) is a new generation of space satellite navigation and positioning system jointly developed by the United States Army, Navy and Air Force in 1970s. Its main purpose is to provide real-time, all-weather and global navigation services for the three major fields of land, sea and air, and to be used for information collection and the working principle of nuclear explosion monitoring satellite positioning.
Some military applications, such as surveillance and emergency communication, are an important part of America's strategy of dominating the world. After more than 20 years of research and experiments, it cost 30 billion dollars. By1March 1994, 24 GPS satellite constellations with global coverage of 98% had been deployed.