BeiDou Navigation Satellite System
|Launch vehicles:||Long March 3B|
|Long March 3C|
BeiDou Navigation Satellite System
The BeiDou Navigation Satellite System (BDS) is a Chinese satellite navigation system that offers precise positioning, navigation, and timing services to users worldwide, regardless of weather conditions and at all times. BDS has found extensive applications in various sectors, including transportation, agriculture, forestry, fisheries, hydrological monitoring, meteorological forecasting, communication, power dispatching, disaster relief, and public security.
BDS is operated by the China National Space Administration (CNSA), which is a governmental agency of the People’s Republic of China. CNSA is headquartered in Haidian, Beijing and is entrusted with the responsibility of overseeing civil space administration and international space cooperation. It was established in 1993 following the division of the Ministry of Aerospace Industry into CNSA and the China Aerospace Science and Technology Corporation (CASC).
The system is composed of two distinct satellite constellations. The initial version, known as the BeiDou Satellite Navigation Experimental System (BeiDou-1), consisted of three satellites and provided limited coverage and navigation services primarily for users in China and nearby regions starting from 2000. BeiDou-1 was retired by the end of 2012.
The second generation, officially known as the BDS or COMPASS (BeiDou-2), became operational in China in December 2011. Initially, it had a partial constellation of 10 satellites in orbit. Since December 2012, BDS has been offering services to customers in the Asia-Pacific region. Notably, within this region, BeiDou provides higher accuracy than GPS.
In 2015, China initiated the launch of the third-generation BeiDou system (BeiDou-3) with the objective of achieving global coverage. The first BDS-3 satellite was successfully launched on March 30th, 2015. Subsequently, on December 27th, 2018, the BeiDou Navigation Satellite System commenced providing global services. The final satellite of BDS-3, marking the 35th satellite, was launched into orbit on June 23rd, 2020. It was announced in 2016 that BeiDou-3 would attain millimeter-level accuracy with post-processing techniques.
On June 23rd, 2020, the most recent BeiDou satellite was launched, signifying the addition of the 55th satellite to the Beidou family. The third iteration of the Beidou Navigation Satellite System now offers comprehensive global coverage for both timing and navigation services, presenting an alternative to Russia’s GLONASS, the European Galileo positioning system operated by EUSPA, and the USSF GPS from the USA.
The BDS is structured into three primary segments: the space segment, the ground segment, and the user segment.
The space segment of BDS encompasses satellites positioned in different orbits: Geostationary Earth Orbit (GEO), Inclined Geo-Synchronous Orbit (IGSO), and Medium Earth Orbit (MEO).
The ground segment of BDS comprises multiple ground stations, including master control stations, time synchronization/uplink stations, monitoring stations, and facilities for the operation and management of inter-satellite links.
The user segment of BDS includes a variety of BDS basic products, systems, and services that are compatible with other navigation systems. This encompasses fundamental products such as chips, modules, and antennae, as well as terminals, application systems, and application services.