The BeiDou Navigation Satellite System (BDS) is a Chinese satellite navigation system which consisted of four satellites (three working satellites and one backup satellite) in the 1st phase and provided an experimental regional navigation system. The satellites were based on the Chinese DFH-3 geostationary communications satellite. Unlike the American GPS, Russian GLONASS, and European Galileo systems, which operate satellites in the Medium Earth Orbit, BeiDou-1 used geostationary satellites orbit which implies that BeiDou-1 does not require a large constellation of satellites however, with the limitation that the coverage is limited to areas on Earth where the satellites are visible.

BeiDou-2 supersedes BeiDou-1 outright. The new system is a constellation of 35 satellites, which include 5 geostationary orbit satellites for backward compatibility with BeiDou-1, and 30 non-geostationary satellites (27 in medium Earth orbit and 3 in inclined geosynchronous orbit) that will offer complete coverage of the globe once commissioned. BeiDou provides two levels of positioning service: open (public) and restricted (military). The public service is available globally to general users while the restricted services are limited the Chinese Military. In addition to the navigation services, BeiDou provides services of Telemetry, AIS Messages and Short Messages.

Stratign’s BeiDou interception system is designed as a fully passive system which makes use of a 5 channel RF receiver cum demodulator to process signals from the 5 geostationary satellites. The system analyses and processes the information in the BeiDou message processor and is made available to the operators for further analysis and display. The system comes with additional back-end servers where the processed information about AIS, Telemetry, etc. can be stored for later reference and analysis.