Introducing the DTED Format

The Digital Terrain Elevation Data (DTED) format is a map format for terrain elevations published by the U.S. National Imagery and Mapping Agency (NIMA). The DTED files contain digital terrain models as rasters. A raster is a georeferenced grid containing a value in each one of its cells. In the case of DTED (and digital terrain models in general) the value indicates the average elevation in the cell. However, this value can indicate any other attribute: surface temperature, surface pressure, nitrogen rating of the soil, and so on.

A DTED file contains a digital terrain model raster that covers a zone of one degree by one degree. The cell size of the raster depends on the DTED level:

• DTED0 provides raw data (approximately 30 to 40 Kb for a file).

• DTED1 provides data that is more detailed.

• DTED2 is the most precise level. It has surface cells that are nine times smaller than those of DTED1. At this degree of precision, a DTED file is enormous (several megabytes).