The BeiDou Navigation Satellite System (BDS) is a Chinese satellite navigation system that provides global coverage. The system is named after the Chinese term for the Big Dipper constellation, which is used in Chinese astrology and is similar in shape to the seven-satellite constellation of the BeiDou system.
The BeiDou system has been in development since the 1990s, and the first satellite was launched in 2000. The system has undergone several upgrades over the years, with the latest upgrade being the BeiDou-3 system.
What is BeiDou-3?
The BeiDou-3 system is the latest upgrade to the BeiDou system. It was officially launched in 2018 and is expected to provide global coverage by the end of 2020. The system consists of 35 satellites, including 27 in medium Earth orbit (MEO), five in geostationary orbit (GEO), and three in inclined geosynchronous orbit (IGSO).
The BeiDou-3 system provides several improvements over the previous BeiDou systems. One of the main improvements is the increased accuracy of the system. The BeiDou-3 system has a positioning accuracy of 10 centimeters, which is an improvement over the 2.5-meter accuracy of the previous BeiDou systems.
Another improvement of the BeiDou-3 system is the increased number of signals. The system provides three types of signals: B1I, B1C, and B2a. The B1I signal is the standard open signal that is available to all users. The B1C signal is a restricted signal that is only available to authorized users. The B2a signal is a new signal that provides improved accuracy and is only available on the BeiDou-3 system.
The BeiDou-3 system also provides improved compatibility with other satellite navigation systems. The system is compatible with the Global Positioning System (GPS), the Russian GLONASS system, and the European Galileo system. This compatibility allows users to receive signals from multiple satellite navigation systems, which improves the accuracy and reliability of the positioning data.
Glossary of Terms
To help users understand the BeiDou-3 system, here is a glossary of terms:
– Satellite Navigation System: A system that uses satellites to provide positioning, navigation, and timing services.
– Global Coverage: The ability of a satellite navigation system to provide services to any location on Earth.
– Medium Earth Orbit (MEO): An orbit that is between low Earth orbit (LEO) and geostationary orbit (GEO). MEO satellites have an orbital period of around 12 hours.
– Geostationary Orbit (GEO): An orbit that is around 36,000 kilometers above the Earth’s surface. GEO satellites have an orbital period of 24 hours, which allows them to remain in a fixed position relative to the Earth’s surface.
– Inclined Geosynchronous Orbit (IGSO): An orbit that is similar to GEO but is inclined at an angle to the equator.
– Positioning Accuracy: The degree of closeness between the measured position and the true position.
– Signal: A radio frequency signal that is transmitted by a satellite and received by a user’s receiver. The signal contains information that is used to determine the user’s position.
– Open Signal: A signal that is available to all users.
– Restricted Signal: A signal that is only available to authorized users.
– Compatibility: The ability of different satellite navigation systems to work together to provide positioning, navigation, and timing services.
Conclusion
The BeiDou-3 system is the latest upgrade to the BeiDou system and provides several improvements over the previous systems. The system has a positioning accuracy of 10 centimeters and provides three types of signals. The system is also compatible with other satellite navigation systems, which improves the accuracy and reliability of the positioning data. With the launch of the BeiDou-3 system, China has become a major player in the satellite navigation industry and is expected to continue to make significant contributions to the field in the future.