Dted Level 1 Data |BEST| Download

DTED (or Digital Terrain Elevation Data) is a standard of digital datasets which consists of a matrix of terrain elevation values, i.e., a Digital Elevation Model. 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:Level 0 has a post spacing of approximately 900 meters.Level 1 has a post spacing of approximately 90 meters.Level 2 has a post spacing of approximately 30 meters

After your products have been selected using a dialog box you can place them into a shopping cart upload the order directly into FedMall. Customers are encouraged to initially order the DLA Map Catalog (CATCDNMCI) and begin receiving it via automatic distribution/subscription. There are a limited number of copies maintained at the Richmond Map Facility, so get yours via automatic distribution/subscription. This catalog is produced every 120 days. For more up-to-date catalog data, the NIPR and SIPR catalogs can be updated via the data download features in FedMall or the SIPRnet, respectively.

DTED is a uniform matrix of terrain elevation values. It provides basic quantitative data for all military systems that require terrain elevation, slope and gross surface roughness information. Data density depends on the level produced.

The Digital Terrain Elevation Data (DTED) Model is a series of gridded elevation models with global coverage at resolutions of 1 kilometer or finer. DTED files are products of the U. S. National Geospatial Intelligence Agency (NGA), formerly the National Imagery and Mapping Agency (NIMA), and before that, the Defense Mapping Agency (DMA). The data is provided as 1-by-1 degree tiles of elevations on geographic grids with product-dependent grid spacing. In addition to NGA's own DTED files, terrain data from Shuttle Radar Topography Mission (SRTM), a cooperative project between NASA and NGA, are also available in DTED format, levels 1 and 2 (see below).

The lowest resolution data is the DTED Level 0, with a grid spacing of 30 arc-seconds, or about 1 kilometer. The DTED files are binary. The files have file names with the extension dtN, where N is the level of the DTED product. You can find published specifications for DTED at the NGA website.

Interestingly enough, all classic DTED is Limited Distribution so Ican't use it in this newsletter. Instead I used the USGS NationalElevation Database (NED) downloaded from the USGSNational Map Seamless Data System. I then used MICRODEMto convert the data to the military DTED 1 and DTED 2 formats (nobody uses theDTED format except for NGA and other Military producers). MICRODEM is written byProfessor Peter Guth at the US Naval Academy. It's a great tool for doingadvanced geospatial stuff - and it's free!

Using File - Import - Surface with the Files of type filter set to DTED files allows us to import NIMA Digital Terrain Elevation Data (DTED) data. This is a NIMA military format for terrain elevation. DTED data occurs in three resolutions: DTED Level 0 data is published in 30 arc second resolution for free public download. Higher resolution DTED Level 1 and Level 2 are available to NIMA's special friends. Manifold reads them all.

The data is packaged as a zip file, which will unzip into a dmed file, and dted and text folders. Within the dted folder will be located other folders containing the individual DTED data tiles, usually in files ending in a .dt* extension such as .dt0. Import the .dt* files to create surfaces.

For example, if in NIMA's server we zoom into the San Francisco Bay area and download the DTED data, after many long minutes of waiting the NIMA server will give us a link to a zip file. We download the zip file, unzip it and find that within the dted folder there are two folders, w122 and w123. Within the w122 folder are four files, n37.avg, n37.dt0, n37.max and n37.min. Within the w123 folder are also four files, also called n37.avg, n37.dt0, n37.max and n37.min. If we import both of the n37.dt0 files (one from the w122 folder and one from the w123 folder), we will end up with two surfaces, one called n37 and the other one called n37 2 (Manifold's default naming scheme appends a "2" to distinguish it from the identically named component already in the project).

Note: OziExplorer version 3.95.4j or later has the ability to download SRTM height data for the region of map being viewed so manual downloading through the site shown below is not required. The SRTM Download option is in OziExplorer on the "3D/Elevation Menu". (OziExplorer3D must be installed for this menu to be visible.)

GDAL supports DTED Levels 0, 1, and 2 elevation data for read access.Elevation data is returned as 16 bit signed integer. Appropriateprojection and georeferencing information is also returned. A variety ofheader fields are returned dataset level metadata.

The SRTM digital elevation data provided on this site has been processed to fill data voids and to facilitate its ease of use by a wide group of potential users. This data is provided in an effort to promote the use of geospatial science and applications for sustainable development and resource conservation in the developing world. Digital elevation models (DEM) for the entire globe, covering all of the countries of the world, are available for download on this site.

The File Transfer Protocol (FTP) is used to distribute geospatial data via its website. Below an exhaustive list of collections that allows to access the FTP site directly. In the FAQ section, the question Is it possible to access files with an FTP client (for example Filezilla, BulletProof FTP, etc.)? will help you for the massive download.

Some digital files are large, often tens of megabytes in size. Plan to download during off-peak hours. It should be noted that the geospatial data have a wide variety of sources, scales, resolutions, projections, spectral resolutions and formats.

DTED files come in different levels depending on the resolution of the data. Level 0 files contain elevation data spaced at 30 arc-second intervals (approximately 1km). Level 1 data are spaced at 3 arc-seconds (approximately 90m) and level 2 data are spaced at 1 arc-second (approximately 30m) intervals. The level is indicated by the metadata within the file as well as the file name extension (.dt0, .dt1, .dt2). This addon will convert any DTED file into a LandSerf .srf file.

DTED Converter was registered on SourceForge.net on Sep 2, 2009, and Converts Digital Terrain Elevation Data (DTED) from one level to another. Dted Converter currently only supports the conversion of data from DTED Level 1 to DTED level 2. The conversion process includes interpolating the 1201*1201 grid of elevation data to 3601*3601, which is the standard for Level 2 DTED Data, then adjusting the header information accordingly. This project is no longer in development due to personal time constraints, however if there are features you desperately need feel free to ask or, of course being open source, you could write it your self and let the developers know :)

Similar to the vector data contained in the GEBCO MillenniumEdition data library, the raster bathymetric and related oceanic data layerscould not be accessed for review within the timeframe of the inventory and aretherefore not included in Table 8.2. However, based on the 1-minute pixel sizeof its raster bathymetric layers, the GEBCO data library likely represent thehighest resolution interpretation of publicly available global seafloorbathymetry. The latest revision of the GEBCO library is the 3rd or CentenaryEdition published in 2003. In regards to updated bathymetry, the latest editionof the GEBCO library includes updates for areas of the Weddell Sea, the NorthAtlantic and the seafloor surrounding New Zealand. The GEBCO data library isavailable for purchase on CD-ROM for £99 non-commercial or £230 forcommercial use, via the British Oceanographic Data Centre website,www.bodc.ac.uk/bodc_products_intro.html. Alternatively areas of up to20°x20° can be downloaded via this URL. The GEBCO data are subject tocopyright under a liberal fair-quotation EULA concerning non-commercialuses.

The level of effort required to create ESRI Grid formattedversions of: the GEBCO bathymetric and terrestrial DEM; the ETopo2; or somederivative 30as DEM(s) combining any of the above three bathymetric sources withthe SRTM30as terrestrial DEM data globally should not exceed 2.5 days. Suchprocessing should also include the creation of basic 2.5d image backgrounds asdepicted in Figures 8.2b and 8.2c below.

The image in Figure 8.2c represents only a small portion of alarger DEM and image background set of data generally suitable for scalessmaller than 1:2 million. These data required less than one day to prepare dueprimarily to the relatively coarse resolution of the ETopo2 bathymetric inputs.In comparison, the LOE associated with the creation of continentally specificDEMs and 2.5d georeferenced image backgrounds suitable for use at scales largerthan the above or representative of scales at or less than 1:1 million are moredifficult to estimate. The creation of such higher resolution georeferencedimages can require anywhere from three to ten days dependant on the process usedand the number of images required at potentially varying scales. Before such aprocess could be considered, issues related to: the elevation break points andcolours used in the base legend; the relative level of 3d exaggeration andpotential sun angle; and whether derivative DEMs based on classifying ranges ofelevation are also required, would at a minimum need to be addressed. Dependingon these considerations, it could be expected that anywhere from three to sixcontinental image backdrops could be created in a day.

As detailed under the Section 8.1.1, however, theconsolidation of the VMap0 vector contour, linear coastline, and bathymetriccontours should be considered. The level of effort associated with integratingthese three data layers would be one day globally once the base data layers havebeen processed. 2b1af7f3a8

Dted Level 1 Data |BEST| Download

Subscribe Form