TanDEM-X Edited DEM: Automated Global Void Filling and Water Flattening

The TanDEM-X mission acquired a global Digital Elevation Model (DEM) between 2011 and 2014 and generated the final DEM product until 2016. Based on the success and high quality of the first DEM a second complete coverage of the Earth was acquired between 2017 and 2021. This DEM is called “TanDEM-X DEM 2020”. Its processing is based on an edited version of the first global TanDEM-X DEM at 30 m resolution. This edited DEM is required to enable the phase unwrapping and significantly accelerates the DEM processing. The paper in hand describes the automatic global editing process for the edited DEM. It explains the detection and discrimination of DEM gaps and the different methods applied to fill these void areas with external information or derived values. Furthermore, for the editing of water bodies different techniques are described which are used to flatten oceans, lakes and rivers respectively. At last, an overview on the status of the global editing process and further improvements are presented.