Automatic Editing of the TanDEM-X Global DEM

The spaceborne TanDEM-X mission successfully acquired and processed a global Digital Elevation Model (DEM) from interferometric bistatic SAR data at X-band. The product has been delivered in 2016 and is characterized by an unprecedented vertical accuracy. It can now be freely accessed by the scientific community in its 12 m (prior the submission of a scientific proposal) and 90 m (global) versions. Such a DEM is unedited, which means that it is the pure result of the interferometric SAR processing and subsequent mosaicking. Residual gaps, resulting from unprocessable data, are still present and water bodies are not flattened to the corresponding shore altitude. This paper reports on the developed algorithms at DLR for a fully automatic editing of the global TanDEM-X DEM, which comprise gaps filling and water editing. The result is a new global gap-free DEM product at 30 m resolution, which can now be used for processing the upcoming TanDEM-X ChangeDEM layer, as well as for a large variety of scientific applications.