DTED (Digital Terrain Elevation Data)
The DTED format was developed for the distribution of gridded elevation data that was assembled by the US Defense Mapping Agency (DMA), now the National Imagery and Mapping Agency (NIMA). DTED data is available at three different resolutions, which are referred to as Level 0, Level 1 and Level 2. Each DTED file contains elevation data for a 1 degree latitude by 1 degree longitude cell. Elevations are stored as signed 2-byte integers with a byte order of MSB (most significant byte first) and units of meters. For latitudes between -50 and 50, pixel dimensions are given by:
DTED Level 0: 30 arcseconds (121 columns x 121 rows)
Latitudes closer to the poles are divided into 4 zones, and the x-size of pixels differs for each zone, getting larger toward the poles.
National Imagery and Mapping Agency (NIMA) of the U.S. Department of Defense
Level 0 data is available for most of the world. Level 1 data is available for the US and is distributed in a different format by the USGS. NIMA will acquire new Level 2 data as a result of the Shuttle Radar Topography Mission (SRTM).
Download Level 0 DEMs: http://126.96.36.199/geospatial/products/DTED/dted.html
NIMA Home: http://www.nima.mil
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