Productivity of TerraSAR-X 3D Data In Urban Areas: A Case Study In Trento

TerraSAR-X (TSX) is supposed to be a revolution for synthetic aperture radar (SAR) imaging because it offers the highest resolution spatial data and is suitable for interferometry. This study aims to validate the performance of TSX high-resolution spotlight (HS) mode data in 3D representations of urban areas. Therefore, a digital surface model (DSM) with a 3-m grid was generated over Trento, Italy, and its quality was validated by comprehensive analyses. The TSX HS DSM matches the reference model well, and the absolute vertical accuracy is +/- 7-8 m. The quality of the topographic estimation is satisfactory due to the suitable normal baseline which yields a more sensitive SAR signal to height differences, transformed into a lower value for the height of ambiguity. The DSM has distortions because of foreshortening, layover and shadows caused by terrain inclination and tall objects on the ground. Dense forests have a negative influence on the results because they are not penetrated by the short wavelengths of the X-band.