The global positioning system of the United States, the GLONASS system of Russia, the Galileo positioning system of the European Union and the Beidou satellite navigation system of China are the four core suppliers of global satellite...
As the world's first positioning system, GPS has been widely known for many years. It is a product of scientific and technological progress. It was initially applied to a project of the U.S. military, and now it has become a good weapon for the conven...
