The Role of Geostationary Earth Orbit Communication Satellites in Chinese Area Positioning System

The Chinese Area Positioning System (CAPS) is an area positioning system based on Geostationary Earth Orbit (GEO) communication satellites. Transponders on the satellites are used to retransmit navigation message and ranging signals generated from the ground master station, while users receive navigation signals to perform navigation and positioning tasks. Meanwhile, CAPS also develops bidirectional communication receivers using abundant transponders resources on Slightly Inclined Geostationary Orbit (SIGSO) communication satellites, thus realizing integration of navigation and communication in the coverage region.