Precise Topographic Mapping Model

This invention successfully integrates photogrammetry and laser measurement for mapping of celestial bodies. Photogrammetry is the science of making 3D models from photographs, which shows better accuracy in the horizontal direction than in the vertical direction. Laser measurement has better accuracy in the vertical direction than in the horizontal. Both methods may have errors of up to several hundred metres. Integrating data from these two sources can remove errors and improve the accuracy of mapping products in both horizontal and vertical directions.

The innovative mapping techniques developed by PolyU were deployed in the characterization and selection of the landing site for Chang’e-3 of China’s lunar missions. The techniques are currently used to map the landing sites of China’s future lunar missions and to produce accurate 3D city models in Hong Kong.