Digital Terrain Elevation Data
Digital Terrain Elevation Data ( DTED ; German digital terrain elevation data ) is a digital terrain model in a grid with regular intervals.
They correspond to the terrain data of the USGS , but were designed by the National Geospatial-Intelligence Agency (NIMA), today's NGA for military purposes.
The DTED files are based on details of the geographical longitude and latitude in WGS84 and are divided into 1 ° packages, which in turn are divided into individual cells with fixed dimensions. A height value is assigned to each cell. The DTED level indicates the cell size:
- in DTED-0 the cell size is 30 arc seconds, which corresponds to about 900 meters
- in DTED-1 the cell width is 3 arc seconds (or about 90 meters)
- in DTED-2 the cell width is 1 arc second (about 30 meters)
The DTED-0 data have a size of around 2 GigaByte (compressed around 800 MegaByte) and can be freely downloaded from the NGA website. Higher DTED levels are not freely available.
The DTED data format is described in the "US Military Specification Digital Terrain Elevation Data (DTED) MIL-D-89020B".
The terrain data is supplemented by Digital Feature Analysis Data , a collection of digital cartographic data from the US Defense Mapping Agency (DMA, today incorporated into the NGA).
See also
- SRTM terrain model data are also freely available and offer higher accuracy (1–3 arc seconds)
- ASTER height profile