Since announcing plans in late 2006 to build its own GNSS system — BeiDou-2 (BDS), China proceeded quickly to establish a fully operational regional system late last year with a clear plan to complete a global system by 2020.
Beginning with its first launch in April 2007, BDS has put 16 satellites in orbit, some in dual launches, with 14 BeiDou space vehicles currently transmitting healthy signals: 5 in geostationary orbits (GEO), 5 in inclined geosynchronous orbits (IGSO), and 4 middle Earth orbit (MEO) spacecraft.
This innovative mixed-satellite design has enabled China to do two key things: first, build a highly accurate and available GNSS capability over the national territory and adjacent regions and, second, encourage early adoption of BeiDou-supported applications.
According to Chinese researchers, most areas in the Asia/Pacific region can receive signals from 8 to 9 BDS satellites on average and achieve a standard positioning service (SPS) level with the following real-time accuracies: horizontal positioning, 10 meters; vertical positioning, 10 meters; velocity, 0.2 meters per second; and one-way timing, 20 nanoseconds.
China is now exploiting the BDS for numerous applications, while evaluating the system’s current performance and planning the final design and implementation of the next stage of the system.
To help us gain further insight into the current status of BDS operations, we turned to Professor Jingnan Liu, former president of Wuhan University where he currently heads the National Engineering Research Center for Satellite Positioning System. Liu is an academician of the Chinese Academy of Engineering with deep expertise in GNSS system technology in general and BeiDou in particular.