What is SRTM “finished” 1 and 3 arc second data?
A. The Shuttle Radar Topography Mission (SRTM) is a joint project between NASA and NGA (National Geospatial-Intelligence Agency) to map the world in three dimensions. SRTM utilized dual Spaceborne Imaging Radar (SIR-C) and dual X-band Synthetic Aperture Radar (X-SAR) configured as a baseline interferometer, acquiring two images at the same time. These images, when combined, can produce a single 3-D image. Flown aboard the NASA Space Shuttle Endeavour February 11-22, 2000, SRTM successfully collected data over 80% of the Earth’s land surface, for all area between 60 degrees N and 56 degrees S latitude. Data Processing SRTM data were processed from raw radar echoes into digital elevation models at the Jet Propulsion Laboratory (JPL) in Pasadena, CA. These original data files had samples spaced (“posted”) at intervals of 1 arc-second of latitude and longitude (about 30 meters at the equator). These data were then edited by the National Geospatial-Intelligence Agency (NGA, formerly the Nat
