DEM extraction from stereo SAR satellite imagery

Automatic Digital Elevation Model (DEM) extraction from stereo SAR satellite images continues to be a challenge. The main difficulty is in obtaining the largest possible number of correct matches, at the same time minimizing the number of false matches and other artifacts and distortions in the derived DEMs. For accepted matches, the highest possible geometric accuracy is desired. This paper describes a number of enhancements in an operational module for DEM extraction: (1) image resampling to quasi-epipolar geometry, (2) uniform area detection and skipping, (3) matching window warping, (4) automatic screening and editing of matches, and (5) large hole interpolation. As a result of these enhancements, more detailed and more accurate DEMs with fewer blunders are extracted with minimum user interaction. This is illustrated by examples for various terrain and land cover conditions