TanDEM-X Performance over Sandy Areas

Abstract

The TanDEM-X mission started in 2010 and comprises the two twin satellites TerraSAR-X and TanDEM-X. Its primary objective is to generate a worldwide, consistent, and high-precision digital elevation model (DEM). Two global coverages have been completed so far, and very good performance has been verified for most of the land masses. However, some areas all around the world still exhibit for different reasons unsatisfactory quality of the data, which deserve to be carefully taken into account. The main scope of this paper is to present a detailed performance analysis over sandy desert areas, which have shown to decrease the quality of the TanDEM-X interferometric products. The influence of several acquisition parameters is evaluated on SAR and InSAR performance by means of statistical analyses as well as long-term repeat-pass acquisitions on defined test sites. The presented investigations allowed then to better characterize the scattering mechanisms occurring at X-band over sandy surfaces, and therefore to opportunely plan a dedicated reacquisition of such affected areas with optimized imaging geometry in order to improve the performance of the final TanDEM-X DEM.