What is BeiDou?

BeiDou is the Global Navigation Satellite System (GNSS) system developed by China to provide all-time, all-weather and high-accuracy positioning, navigation and timing services to global users. The service is named after the Big Dipper constellation, which is called as BeiDou in Chinese.

China launched the first generation of its BeiDou navigation system (BeiDou-1) in 2000 with three satellites in the constellation. The second generation BeiDou-2, also known as COMPASS, became operational in the year 2012.

The full BeiDou orbital constellation (BeiDou-3) will be complete by 2020 with 35 satellites in orbit. The break up of the 35 satellites will be as follows:

• 5 BeiDou-G satellites in the geostationary orbit (GEO)
• 27 BeiDou-M satellites in medium Earth orbit (MEO)
• 3 BeiDou-I satellites in inclined geosynchronous orbits (IGSO)

The BeiDou Navigation Satellite System (BDS) has three segments: the space segment, the ground segment and the user segment. 

• Space Segment: The space segment is a hybrid navigation constellation consisting of GEO, IGSO and MEO satellites.  
• Ground Segment: The ground segment consists of various ground stations, including master control stations, time synchronization and uplink stations, as well as a number of monitoring stations.  
• User segment: The user segment consists of chips, modules and antennas, as well as terminals, application systems and application services, which may be compatible with other GNSS systems.

The service performance standards of BeiDou are:

• BeiDou Service coverage: Global positioning accuracy - Horizontal 10 meters and Vertical 10 meters (The positioning accuracy in Asia-Pacific region is 5 meters horizontally and 5 meters vertically)
• Velocity measurement accuracy: 0.2 m/s
• Timing accuracy: 20 nanoseconds
• System service availability: More than 95%

Click here to learn more about BeiDou Frequency Bands.