On 28 Sept. 2018 DLR made available to the public the 90 metre resolution global elevation model from the TanDEM-X mission. The data set can now be downloaded free of charge via the new EOC download service.
The TanDEM-X model was generated at EOC from a homogenous database and is considerably more precise than other global data sets. For large parts of the earth the elevation accuracy of the data is one metre! Besides the reduced surface model resulting from the TanDEM-X mission that took place from 2010 to 2015, a second elevation data set can be obtained via the download service. The first global, radar-based elevation model was created in 2000 as part of the Shuttle Radar Topography Mission. A comparison of the two data sets offers fascinating insights into the dynamics of the earth's surface. For example, millions of tons of soil and rocks were moved in the course of lignite opencast mining in the Oberlausitz (Upper Lusatia region). The elevation models that were produced at DLR impressively document the changes that have taken place over the past two decades.
With the new service the elevation data can be downloaded with a few mouse clicks after simple online registration. Different elevation models can also be directly compared with each other in the map browser of the EOC Geoservice, making possible the discovery of traces of human activity, volcanic eruptions, or glacier movement. Additional data sets, for example showing global forest coverage or image data from the Sentinel-2 satellite, are to follow soon. Moreover, daily-updated satellite image mosaics, settlement masks, global snow cover, and ozone concentrations can be viewed in the map browser of the EOC Geoservice and directly integrated in user applications.
The data shown here are only a tiny extract from the enormous resources of the German Satellite Data Archive (D-SDA), where data from current and past missions are stored and maintained for the use of scientists. Long-term environmental change can be detected, documented and analysed with the time series available there. The TanDEM-X mission also continues to supply new data. Currently, recordings are being made for a global "ChangeDEM", the next generation of X-band elevation models.
Lignite opencast mining in the Oberlausitz between Cottbus and Dresden (to the west in the image the Welzow-Süd opencast mine, to the east the Nochten mine). The X-band SAR elevation models from the SRTM mission of 2000 and the TanDEM-X Mission of 2011-2012 clearly show the gigantic movements of mass during opencast mining and backfilling within a decade. The net change elevation model was produced by subtracting the models of the two missions from each other. It shows backfilling zones (yellow-orange) and new excavations (blue) between 2000 and 2011/2012.
EOC Download Service (technical implementation):
TanDEM-X Project (science coordination):
Irena Hajnsek and Thomas Busche
TanDEM-X science coordination: