Technical Note on Quality Assessment for Sentinel-1 ARD from Very High Resolution DEM

The production of radar Analysis Ready-Data requires the processing of calibration steps, which could either consider a flat surface (ellipsoid) or take into account the topography. This last processing is entitled Radiometric Terrain Correction (RTC), and requires a Digital Elevation Model to be applied. The goal of this study is to compare the quality of the RTC processing using Copernicus DEM GLO-30 (1” of GSD, approx. 30m at equator) vs. Very-High Resolution DEMs of France and the Trento province of Italy (1m to 2m of GSD). A particular attention is given to steep areas where an accurate model of the terrain is critical to the RTC process.