Shuttle Radar Topography Mission 1 Arc and 3 Arc Second Digital Terrain Elevation Data - National Geospatial Data Asset (NGDA)

The Shuttle Radar Topography Mission (SRTM) was a partnership between NASA and the National Geospatial-Intelligence Agency (NGA). Flown aboard the NASA Space Shuttle Endeavour (11-22 February 2000), SRTM fulfilled its mission to map the world in three dimensions. The USGS is under agreement with NGA and NASA's Jet Propulsion Laboratory to distribute SRTM elevation products derived from the C-band radar data. SRTM utilized interferomic C-band Spaceborne Imaging Radar to generate elevation data over 80 percent of the Earth's land surface.

The SRTM collection has been edited to delineate and flatten water bodies, better define coastlines, remove spikes and wells, and fill small voids.