Value-Added Data Products

Value-Added Data Products is the line of processed geospatial datasets that Twenty First Century Aerospace Technology (21AT) makes from imagery collected by its own Beijing series of optical Earth-observation satellites. It serves organisations that need orthoimagery, elevation data and 3D terrain or city models over large areas; the provider describes its ortho, surface and elevation products as an important part of national fundamental geographic information.

The line has five products. The Digital Ortho Map (DOM, L4) is made by differential rectification, fusion, colour adjustment and mosaicking of satellite images, combining photographic detail with map geometry. The Digital Surface Model (DSM) records surface height including buildings, bridges and trees, and the Digital Elevation Model (DEM) records bare-earth height, both as regular height grids produced from Beijing-3 in-track stereo and tri-stereo pairs. The 3D Mesh product uses stereo imaging, high-precision matching and texture mapping to build realistic 3D scenes, and the White Architecture Model uses AI to extract building outlines and heights from true orthoimagery and the DSM.

For customer-defined areas 21AT also selects, orthorectifies, mosaics, colour-balances and crops imagery (including Beijing-2 ortho and mosaic products), and can tile the result into multilevel pyramids served as an online basemap. In a 2023 presentation on its Beijing-3 3D products, the provider cited the Beijing-3 satellites' global availability, fast delivery, large scale, low cost and stable quality, and a 2025 cover story in the National Remote Sensing Bulletin reports the 3D products' use in natural-resource survey and supervision, digital-twin city construction and geological-hazard emergency management.