Evaluation of elevation derived from interferometric SAR data with DEM

Abstract

Interferometric SAR is a stereoscopic method to obtain contours of ground elevation. A lot of studies have been done to derive the elevation map from SAR data, however, only few studies have been reported to examine the difference between the elevation map and DEM (Digital Elevation Model). In this paper, the authors compare the surface elevation map derived from interferometric SAR data with DEM, and evaluate the error distribution of the elevation map. The root mean squared error is found to be 33 m, and it agrees with the absolute vertical accuracy of DEM. The error distribution is also evaluated, and is verified to be approximately Gaussian. The large errors tend to appear locally at shadowed or steep sloped area, where phase noise or phase unwrapping error is large.