Resolution enhancement of DEM using photometric stereo method in time-varying shadowed region

Abstract

Generation of high-resolution Digital Elevation Model (DEM) is essential for space missions like an investigation of the topographic feature, a selection of landing site or a path planning of rover. Fusion of image which contains high-frequency information on the terrain surface and depth information which gives sparse information is an important topic in the generation of DEM. In this paper, the photometric stereo method is used to generate the surface normal information of shadowed region in the crater. Then, the surface normal is fused with interpolated DEM from ground truth DEM. The fusion enhances the lateral resolution of interpolated DEM and generates details of the ground truth DEM which is not shown in interpolated DEM. This method can be adapted to enhance DEM for near polar region, which has a large variation in shadow and has many image dataset due to orbiter's flight orbit.