BeiDou Navigation Satellite System (China)
China has started the implementation of a GNSS system known as BeiDou Navigation Satellite System (BDS). The system is being implemented in two phases: the initial phase provides regional coverage, while the second phase will provide global coverage.
The initial phase of the BeiDou system officially became operational in December 2012, providing coverage for the Asia Pacific region. The regional BeiDou space segment has five Geostationary Earth Orbit (GEO) satellites, five Inclined Geosynchronous Orbit (IGSO) satellites and four Medium Earth Orbit (MEO) satellites (summarized in Table 6).
The second phase of the BeiDou system is planned to be completed by the end of 2020 and will provide global coverage with enhanced regional coverage. The space segment will consist of a constellation of 5 GEO, 3 IGSO and 27 MEO satellites, as shown in Table 7.
Table 6: Regional BeiDou Satellite Constellation
Satellites | 5 Geo | 5 IGSO | 4 MEO |
Orbital Inclination | - | 55 degrees | 55 degrees |
Orbit Radius | 35,787 km | 35,787 km | 21,528 km |
Table 7: Planned Global BeiDou Satellite Constellation
Satellites | 5 GEO | 3 IGSO | 27 MEO |
Orbital Planes | - | - | 3 |
Orbital Inclination | - | 55 degrees | 55 degrees |
Orbit Radius | 35,787 km | 35,787 km | 21,525 km |
BeiDou Signals
The BeiDou signals, based on CDMA technology, are summarized in Table 8. Three levels of service will be provided:
Table 8: BeiDou Signal Characteristics
Designation | Frequency | Description |
B1 | 1561.098 MHz | B1 provides both public service signals and restricted service signals. |
B2 | 1207.140 MHz | B2 provides both public service signals and restricted service signals. |
B3 | 1268.520 MHz | B3 provides restricted service signals only. |