TanDEM-X DEM 2020: Product release and quality assessments

Abstract

This contribution introduces the newly developed global TanDEM-X DEM 2020 data set. The German TanDEM-X mission, consisting of two satellites operating in close formation since 2010, serves as the foundation for generating bistatic interferometric SAR data. Following the conclusion of data acquisition for the initial global TanDEM-X Digital Elevation Model (DEM) between 2010 and 2014 [1], the TanDEM-X mission systematically acquired data mainly between September 2017 and mid-2021 to create a new global DEM, referred to as the “TanDEM-X DEM 2020”. The main focus of this presentation lies in the production process and preliminary results of global evaluation measures. The primary distinctions between the TanDEM-X DEM 2020 and its predecessor (2010-2014) are the new and independent time frame and an updated interferometric processing technique which minimizes phase unwrapping errors, allowing for a mainly single-coverage acquisition strategy except for challenging terrain. Each DEM scene is pre-calibrated against the global TanDEM-X DEM optimizing the DEM calibration process while maintaining exceptional accuracy. Key features of digital elevation models are performance and accuracy, therefore the TanDEM-X DEM 2020 will be quantitatively assessed against reference data including ICESat, ICESat-2, GPS tracks and, importantly, the first global TanDEM-X DEM. Additionally, a qualitative evaluation is conducted exemplarily on selected sites, highlighting the advantages of interferometric DEMs: global coverage, high accuracy and homogeneity. In this contribution we present the production process, first quality assessments and release of a new global digital elevation dataset: TanDEM-X DEM 2020. This DEM offers an actual topographic dataset and facilitates global-scale monitoring of topographic changes through comparisons with the earlier TanDEM-X DEM. The TanDEM-X DEM 2020 product is expected to become publicly available to the scientific community by mid-2025 via DLR’s EOWEB portal. References: [1] Rizzoli, P., Martone, M., Gonzalez, C., Wecklich, C., Borla Tridon, D., Bräutigam, B., Bachmann, M., Schulze, D., Fritz, T., Huber, M., Wessel, B., Krieger, G., Zink, M., and Moreira, A. (2017): Generation and performance assessment of the global TanDEM-X digital elevation model, ISPRS J. Photogram. Remote Sens., 132, 119-139.