The China DMC+4 satellite, known officially as Beijing-1, is a low-cost earth observation small satellite that was launched as part of the first generation of satellites in the Disaster Monitoring Constellation (DMC). It carries two payloads that provide high-resolution panchromatic images alongside medium-resolution (32-metre) multi-spectral images with an ultra-wide 600 km imaging swath.


Beijing-1 provides the Chinese government and commercial users with information on agriculture, water resources, environment and disaster monitoring throughout China. The satellite is also used extensively for monitoring urban development and pollution, and to generate digital maps of China using the high-resolution panchromatic imager.

The satellite is capable of continuously imaging Chinese territory even at the longest landmass track (3000 km) and transmits images to the ground station in Beijing in real-time at high speed (40Mbps) with on-board programmable compression. Image data gathered outside the reach of the ground station is stored on-board in a hard disc mass storage device for retrieval at night or later on demand.

Beijing-1 and the DMC mission

The DMC is an international collaboration of several countries each contributing an advanced yet low-cost satellite to the constellation and sharing the data. The DMC constellation is the first to be specifically designed and dedicated to monitoring natural and man-made disasters.

The original DMC partners were:

  • Algeria (AlSat)
  • Turkey (BilSat)
  • Nigeria (NigeriaSat)
  • China (Beijing-1)
  • UK (UKDMC).

The satellites were to be launched into the same orbit and phased equally around the orbit.

AlSat was the first to be launched in late November 2002, the next three satellites were launched in September 2003 and the Beijing-1 was launched on 27 October 2005. The five satellites were networked together with the objective of providing a daily global imaging capability at medium resolution (30-40 m), in 3-4 spectral bands, for rapid response disaster monitoring and mitigation. Beijing-1 has functioned correctly for the whole duration of the DMC mission.

The DMC satellites have subsequently been used for an evaluation of automatic registration and change detection as part of the On Board Data Handling research group.