Where do our current digital elevation data come from?

This blog is by Gustavus student Andrew Byron as part of his Remote Sensing of Environment class.

This past February, NASA celebrated the 10th anniversary of the completion of the Shuttle Radar Topography Mission (SRTM), an effort to remotely sense the topography of earth’s surface using shuttle-borne radar. The system actively mapped a 139 mile wide swath of the earth’s surface while orbiting upside-down, tail first, at just under 17,000 miles per hour. In just eleven days, the mission had made 176 complete orbits of the earth and mapped land elevation from 60 degrees south to 60 degrees north. The data collected by this mission is the source for most 30 meter resolution Digital Elevation Models (DEMs). These models can in turn be used for storm surge analysis of hurricanes, creating shaded relief maps, modeling surface water flow, building flight simulations, and many other applications. For more information on the Shuttle Radar Topography Mission, visit NASA’s Jet Propulsion Lab at http://www2.jpl.nasa.gov/srtm/.