Beidou-2 M1

BD 2M (Beidou 2M) and BD 2I (Beidou 2I) satellites are the MEO and IGSO components of the 2nd phase of the Chinese Beidou (Compass) satellite navigation system, which, in contrast to GPS and GLONASS, uses both geostationary satellites and satellites in intermediate orbit. This series provides the satellites for the inclined geostationary (IGSO) constellation called "Compass-I" and the prototypes for the intermediate constellation called "Compass-M" in 12-hours orbits. The satellites are based on the DFH-3 Bus. They feature a phased array antenna for navigation signals and a laser retroreflector.