5.A.i.c. Extracts from Prototype National Geospatial-Intelligence Agency (formerly the National Imagery and Mapping Agency (NIMA) Documentation of DTED Level 0 The following text is from NIMA's provisional description of DTED Level 0 (from NIMA's Web site) at the time of release of DTED Level 0: "In support of military applications, the National Imagery and Mapping Agency (NIMA) has developed a standard digital dataset (Digital Terrain Elevation Data (DTED) Level 0) which may be of value to scientific, technical, and other communities. This DTED product is a uniform matrix of terrain elevation values which provides basic quantitative data for systems and applications that require terrain elevation, slope, and/or surface roughness information. DTED Level 0 elevation post spacing is 30 arc-second (nominally one kilometer). In addition to this discrete elevation file, a separate binary file provides the minimum, maximum, and mean elevation values computed in 30 arc-second square areas (organized by one degree cell). Finally, DTED Level 0 contains the NIMA Digital Mean Elevation Data . . . providing minimum, maximum, and mean elevation values and standard deviation for each 15 minute by 15 minute area in a one degree cell. This initial prototype release is a "thinned" data file extracted from the NIMA DTED Level 1 holdings in combination with other publicly releasable data. As such, this version of DTED Level 0 is a step toward a worldwide digital terrain dataset. Efforts to fully populate a worldwide DTED Level 0 dataset continue . . . The current DTED Level 0 and subsequent releases will be updated consistent with established NIMA production maintenance procedures.
|