A new global digital elevation model (DEM) has been released. NASADEM is a reprocessing of Shuttle Radar Topography Mission (SRTM) data to improve height accuracy and to infill missing elevation data. The data was improved through the use of algorithms and data that wasn’t available at the time of the original SRTM data release. Missing data within SRTM was refined with ASTER GDEM elevations.
From NASA‘s technical details about the process:
We will reprocess the entire SRTM dataset from raw sensor measurements with validated improvements to the original processing algorithms. We will incorporate GLAS data to remove artifacts at the optimal step in the SRTM processing chain. We will merge the improved SRTM strip DEMs, refined ASTER and GDEM V2 DEMs, and GLAS data using the SRTM mosaic software to create a seamless, void-filled NASADEM. In addition, we will provide several new data layers not publicly available from the original SRTM processing: interferometric coherence, radar backscatter, radar incidence angle to enable radiometric correction, and a radar backscatter image mosaic to be used as a layer for global classification of land cover and land use.
The newly available NASADEM data products are available with a 1 arc second resolution. Other radar products were released with the updated DEM. All NASADEM products are available for land between 60° N and 56° S latitude, representing 80% of all the Earth’s landmasses. All datasets can be downloaded from NASA’s Land Processes DAAC (LP DAAC)