BeiDou (北斗卫星导航系统) – The BeiDou Navigation Satellite System is a Chinese satellite navigation system. It consists of two separate satellite constellations. Wikipedia
Beidou Satellite Navigation System ( Beidou System for short ) is a satellite navigation system that can provide users around the world with all-weather, all-weather, high-precision positioning, navigation and timing services. There are three generations of the Beidou system. The Beidou system since the second generation is officially called the “Beidou Satellite Navigation System.”
The Beidou No. 1 system (the first-generation Beidou system) provides regional positioning services by three satellites. Since 2000, the system has mainly provided navigation services in China. In December 2012, the life of the last Beidou-1 satellite expired, and the Beidou satellite navigation test system ceased operation.
The Beidou-2 system (the second-generation Beidou system) is a global satellite navigation system containing 16 satellites, including 6 geostationary orbit satellites, 6 tilted geosynchronous orbit satellites, and 4 medium earth orbit satellites. In November 2012, the second-generation Beidou system began to provide users with regional positioning services in the Asia-Pacific region.
The Beidou-3 system (the third-generation Beidou system) consists of three satellites in different orbits, including 24 medium-circular earth orbit satellites (covering the world), 3 tilted geostationary orbit satellites (covering most of the Asia-Pacific region) and 3 Geostationary satellites (covering China). Beidou-3 opened the Beidou system’s global positioning function in advance in 2018. The Beidou No. 3 system was opened on July 31, 2020. The Beidou Satellite Navigation System (BDS), the United States Global Positioning System (GPS), the Russian Global Navigation Satellite System (GLONASS) and the European Union Galileo Positioning System (Galileo) are the four core suppliers of global satellite navigation systems recognized by the United Nations Satellite Navigation Commission .
“Beidou Satellite Navigation System” is the official name of this system, it is named after the Big Dipper . “Beidou” literally means “the battle in the north”, which is the name given to the seven brightest stars in Ursa Major by ancient Chinese astronomers . Historically, people used these seven stars to find the North Star to determine the direction. Therefore, the name “Beidou” implies the purpose of this satellite navigation system.