TanDEM-X (TerraSAR-X add-on for Digital Elevation Measurements) is an Earth observation radar mission that consists of a SAR interferometer built by two almost identical satellites flying in close formation. With a typical separation between the satellites of 120m to 500m a global Digital Elevation Model (DEM) has been generated.
Main objective of the TanDEM-X mission is to create a precise 3D map of the Earth’s land surfaces that is homogeneous in quality and unprecedented in accuracy. The data acquisition was completed in January 2015 and production of the global DEM was completed in September 2016. The absolute height error is with about 1m an order of magnitude below the 10m requirement.
The TanDEM-X 90m DEM offered here for download is a product derived from the global Digital Elevation Model (DEM) with a 0.4arcsec (12m) posting, and has a reduced pixel spacing of 3 arcseconds (arsec), which corresponds to approximately 90m at the equator. It covers with 150 Mio sqkm all Earth’s landmasses from pole to pole.
The TanDEM-X DEM represents a Digital Surface Model (DSM), means it does not represent the bare earth surface, when e.g. vegetation or man-made objects are present.
You can find more information here: https://tandemx-90m.dlr.de
Download data from here: https://download.geoservice.dlr.de/TDM90/
Download KMZ index: https://tandemx-science.dlr.de/map_overlays/TanDEM-X_Science_IDEM_Available_Status.kmz