Reconstruction and Evaluation of DEMs From Bistatic Tandem-X SAR in Mountainous and Coastal Areas of China

TerraSAR-X add-on for Digital Elevation Measurements (TanDEM-X) mission is designed to generate 3-D images of the Earth as first bistatic synthetic aperture radar (SAR). However, few quantitative studies TanDEM-X digital elevation model (DEM) quality validation have been conducted specifically in China. This article presents an iterative method high-resolution DEMs and assesses vertical accuracy with high-accuracy GPS observations, 1 arc second global available [Advanced Land Observing Satellite World 3-D-30 m v2.2, Advanced Spaceborne Thermal Emission Reflection Radiometer Global Model (ASTER GDEM) v3, Shuttle Radar Topography Mission (SRTM) v3.1, NASADEM, X-band SRTM], 90 DEM. The results demonstrate remarkable consistency coastal areas root mean square error 1.7 90% linear (LE90) 0.4 m, whereas 3–4 times weaker accuracies steep mountainous areas. A positive bias 1–2 overall LE90 measure exists dense vegetation steep-slope DEM-based SAR interferometry deformation uncertainty simulation indicates a low or even negligible topographic contribution 2–4 mm less than It that DEM performs better other shows consistence SRTM C-band area. As excellent source up-to-date information, are expected be advantage understanding dynamic land use changes improving identification delineation lands, landslides, earthquakes disasters.