Is there a GPS positioning system in the world?

As of August 2021, China, the United States, and Russia have their own global satellite positioning systems.

GPS, or Global Positioning System, is a medium-distance circular orbit satellite navigation system that combines satellite and communication development technologies and uses navigation satellites for timing and ranging. GPS is a new generation satellite navigation and positioning system developed in the United States in the 1970s and fully completed in 1994. It has the ability to implement all-round three-dimensional navigation and positioning on sea, land and air.

After nearly ten years of use by my country’s surveying and mapping departments, it has been shown that the global positioning system has won the trust of the majority of surveying and mapping workers with its characteristics of all-weather, high precision, automation, and high efficiency, and has been successfully used in geodetic surveying. , engineering surveying, aerial photogrammetry, vehicle navigation and control, crustal movement monitoring, and engineering deformation monitoring have brought about a profound technological revolution.

The development history of the global satellite positioning system

Since 1978, more than 50 GPS and NAVSTAR satellites have been put into orbit. The predecessor of the GPS system was a meridian satellite positioning system (Transit) developed by the US military. It was developed in 1958 and officially put into use in 1964. The system works with a star network of 5 to 6 satellites, orbits the earth up to 13 times a day, and cannot give an altitude.

It is also unsatisfactory in terms of positioning accuracy. However, the meridian system enabled the R&D department to gain preliminary experience in satellite positioning and verified the feasibility of positioning by satellite systems, paving the way for the development of the GPS system. Because satellite positioning shows great advantages in navigation and the meridian system has huge flaws in submarine and ship navigation.