Shuttle Radar Topography Mission (SRTM) Images

Culminating more than four years of processing data, NASA and the  National Geospatial-Intelligence Agency (NGA) have completed Earth's  most  extensive global topographic map. The mission is a collaboration among NASA, NGA, and the German and Italian space agencies. For 11 days in February 2000,  the space shuttle Endeavour conducted the Shuttle Radar Topography Mission  (SRTM) using C-Band and X-Band interferometric synthetic aperture radars to  acquire topographic data over 80% of  the Earth's land mass, creating the first-ever near-global data set of land elevations.  This data was used to produce topographic maps (digital elevation maps) 30  times as precise as the best global maps used today.  The SRTM   system gathered    data at the rate of 40,000 per minute over land.  They reveal for the first time large, detailed swaths of Earth's topography previously  obscured by  persistent cloudiness. The data will benefit scientists, engineers, government agencies and the public with an ever-growing array of uses. The SRTM radar system mapped Earth from 56 degrees south to 60 degrees  north of the equator. The resolution of the publicly available data is three arc-seconds (1/1,200th of a degree of latitude and longitude, about  295 feet, at Earth's equator).  The final data release covers Australia and New Zealand in unprecedented uniform detail. It also covers more than 1,000 islands     comprising much of Polynesia and Melanesia in the South Pacific, as    well as islands in  the South Indian and Atlantic oceans.  SRTM data are being used for applications ranging from land use planning  to "virtual" Earth exploration.    Currently, the mission's homepage "http://www.jpl.nasa.gov/srtm" provides direct  access to recently obtained earth images.   The Shuttle Radar  Topography Mission C-band  data for North America and South America are available to the public.  A list of complete public data set is available at "http://www2.jpl.nasa.gov/srtm/dataprod.htm"  The data specifications are within the following parameters:  30-meter X 30-meter spatial sampling with 16 meter absolute vertical height  accuracy,  10-meter relative vertical height accuracy, and 20-meter absolute horizontal  circular accuracy.  From the JPL Mission Products Summary,   "http://www.jpl.nasa.gov/srtm/dataprelimdescriptions.html". The primary products of the SRTM mission are the digital elevation maps of most of the Earth's surface.  Visualized images of these maps are available for viewing online. Below you will find descriptions of the types of images that  are being generated:       
      
-  Radar Image              
-  Radar Image with Color as Height             
-  Radar Image with Color Wrapped Fringes             
-Shaded Relief              
-  Perspective View with B/W Radar Image Overlaid  
-  Perspective View with Radar Image Overlaid, Color as Height      
-  Perspective View of Shaded Relief              
-  Perspective View
with Landsat or other Image Overlaid              
-  Contour Map - B/W with Contour Lines              
-  Stereo Pair             
-  Anaglypgh            

The SRTM radar contained two types of antenna panels, C-band and X-band. The near-global topographic maps of Earth called Digital Elevation Models (DEMs) are made from the C-band radar data.  These data were processed at  the Jet  Propulsion Laboratory and are being distributed through the United States  Geological Survey's EROS Data Center. Data from the X-band radar are used to create slightly higher resolution DEMs  but without the global coverage of the C-band radar. The SRTM X-band radar data are being processed and distributed by the German Aerospace Center, DLR.

Tags: earth-science, geomorphic-landforms-processes, land-surface, land-use-land-cover, landscape, radar, spectral-engineering, topography
Organization: National Aeronautics and Space Administration