Densification of Dtm Grid Data Using Single Satellite Imagery

Digital Terrain Models (DTMs) are simply regular grids of elevation measurements over the land surface. DTMs are mainly extracted by applying the technique of stereo measurements on images available from photogrammetry and remote sensing. Enormous amounts of local and global DTM data with different specifications are now available. However, there are many geoscience and engineering applications which need denser DTM grid data than available. Fortunately, advanced space technology has provided much single (if not stereo) high-resolution satellite imageries almost worldwide. Nevertheless, in cases where only monocular images are available, reconstruction of the object surfaces becomes more difficult. Shape from Shading (SFS) is one of the methods to derive the geometric information about the objects from the analysis of the monocular images. This paper discusses the use of SFS methods with single high resolution satellite imagery to densify regular grids of heights. Three different methodologies are briefly explained and then implemented with both simulated and real data. Moreover, classification techniques are used to fine tune the albedo coefficient in the irradiance model. Numerical results are briefly discussed.