Relative Height Accuracy Estimation Method for InSAR-Based DEMs

Digital elevation models (DEMs) are of fundamental importance for a broad range of commercial and scientific applications. The relative height accuracy of the DEM is one of the most important quality parameters as it refers to the local differences among adjacent elevation values. A direct comparison against a reliable reference DEM is only possible for some single regions where an accurate model similar in resolution is already available. DEMs generated from interferometric synthetic aperture radar (InSAR) can be analyzed with respect to the relative height accuracy based on the data itself. This paper introduces a novel approach to estimate the relative height accuracy. The analysis is based on the well-known statistical characteristics of SAR interferograms and is designed as a specification check for global DEM generation. First results of evaluation of the relative height accuracy are presented for TanDEM-X data.