The DTED filter imports uniform lattices from several two-dimensional elevation grid file formats, also known as digital terrain elevation data or DTED data sets.
File Description
Digital Terrain Elevation Data .DTED are grids originally produced by the United States National Imaging and Mapping Agency ( NIMA). The files contain latitude/longitude coordinates with the Z units in meters. The .DTED format is a standard of digital datasets which consists of a matrix of terrain elevation values. The standard was originally developed to support aircraft radar simulation and predication.
DTED supports many applications, including line-of-sight analyses, terrain profiling, 3D terrain visualization, mission planning/rehearsal, and modeling and simulation. DTED is a standard National Geospatial-Intelligence Agency (NGA) product that provides medium resolution, quantitative data in a digital format for military system applications that require terrain elevation.
File Format
There are multiple "levels" of DTED files. The DTED format for level 0, 1 and 2 is described in U.S. Military Specification Digital Terrain Elevation Data (DTED) MIL-PRF-89020B, and amongst other parameters describes the resolution for each level. DTED data is stored in a big endian format where negative numbers are signed magnitude.
Level 0 files .DT0 are 1-degree square blocks with 30 arc-second spacing in latitude direction, similar to GTOPO 30 files.
Level 1 files .DT1 use three arc-second spacing. Level 1 has a post spacing of ca. 90 meters which results in the following table:
|
Zone |
Latitude |
Interval Latitude (arc sec) |
Interval Longitude (arc sec) |
|
I |
0-50 degrees (North-South) |
3 |
3 |
|
II |
50-70 degrees (North-South) |
3 |
6 |
|
III |
70-75 degrees (North-South) |
3 |
9 |
|
IV |
75-80 degrees (North-South) |
3 |
12 |
|
V |
80-90 degrees (North-South) |
3 |
18 |
Level 2 files .DT2 use one arc-second spacing.
In addition three more levels (3, 4 and 5) at increasing resolution have been proposed, but not yet standardized.
File Name Extensions
DTED .DT0, .DT1, .DT2
Format(s) Supported for Import
2D uniform lattice; 8-, 16-, 32-bit integer, float, double
Import Method
Choose the File | Import command.
See Also