SRTM

SRTM, the Shuttle Radar Topography Mission, was an 11-day Space Shuttle Endeavour flight in February 2000 that mapped land elevation by single-pass radar interferometry. A C-band and an X-band radar, the second antenna on a 60 m mast, imaged about 80 percent of Earth’s land between 56 degrees south and 60 degrees north. The processed product is gridded at 1 arc-second, roughly 30 m, for the United States and originally 3 arc-seconds globally, with vertical accuracy better than 16 m. SRTM is a land digital elevation model; it carries no bathymetry and is often paired with bathymetric grids such as ETOPO for combined relief.