  160px|thumb|right|the beidou system's logo. the beidou navigation satellite system (bds, ) is a chinese satellite navigation system. it consists of two separate satellite constellations â a limited test system that has been operating since 2000, and a full-scale global navigation system that is currently under construction. the first beidou system, officially called the beidou satellite navigation experimental system () and also known as beidou-1, consists of three satellites and offers limited coverage and applications. it has been offering navigation services, mainly for customers in china and neighboring regions, since 2000. the second generation of the system, officially called the beidou satellite navigation system (bds) and also known as compass or beidou-2, will be a global satellite navigation system consisting of 35 satellites, and is under construction as of january 2013. it became operational in china in december 2011, with 10 satellites in use, and began offering services to customers in the asia-pacific region in december 2012. it is planned to begin serving global customers upon its completion in 2020. ==nomenclature== the beidou navigation system is named after the big dipper constellation, which is known in chinese as bÄidÇu. the name literally means "northern dipper", the name given by ancient chinese astronomers to the seven brightest stars of the ursa major constellation. historically, this set of stars was used in navigation to locate the north star polaris. as such, the name beidou also serves as a metaphor for the purpose of the satellite navigation system. ==history== ===conception and initial development=== the original idea of a chinese satellite navigation system was conceived by chen fangyun and his colleagues in the 1980s.åæè®° ââæ¢ç§ä¸­å½åæå«æå¯¼èªå®ä½ç³»ç» according to the china national space administration, the d
Aids_to_navigation Satellite_navigation_systems Satellites_of_China Science_and_technology_in_the_People\'s_Republic_of_China Time_signal_radio_stations