Beijing-2 (TripleSat Constellation)

Beijing-2 is the optical Earth observation constellation operated by Twenty First Century Aerospace Technology (21AT) and marketed internationally by Singapore-based Twenty First Century Aerospace Technology (Asia), 21AT Asia, as the TripleSat Constellation. It supplies sub-metre optical imagery for government administration, resource and environmental monitoring, national security and mapping, in China and abroad.

Three identical SSTL-300S1 satellites, built by Surrey Satellite Technology Ltd and launched together in July 2015, fly 120 degrees apart in one sun-synchronous orbit; 21AT's parameter sheet adds a fourth on-orbit back-up satellite. They capture 0.8-metre panchromatic and 3.2-metre multispectral imagery (blue, green, red and near-infrared) over a swath of about 24 km, with ±45° off-nadir pointing; 21AT gives the constellation's design capability as a revisit of any point on Earth within one to two days. 21AT runs observation planning, satellite control, data reception and processing through a ground system it built itself. Raw data are decoded and processed (radiometric correction, denoising, CCD stitching, band registration, geometric correction and MTF compensation) into standard scene products with RPC files, which 21AT offers to customers worldwide; 21AT Asia lists GeoTIFF/TIFF delivery and processing levels from L1 to ortho-rectified L4. The 21AT Imagery Portal lists Beijing-2 (TripleSat) imagery for archive search and ordering but states that new TripleSat tasking is not available, so buyers should confirm acquisition options with 21AT.

21AT describes Beijing-2 as China's first civil commercial remote sensing satellite project approved by the National Development and Reform Commission. Published uses include statewide base maps of Queensland, Australia, supplied through Earth-i for the state's Department of Natural Resources and Mines from 2016 to 2018, and four monthly national coverages of the Netherlands for the Netherlands Space Office in 2017.