Digital terrain elevation data dted is a standard mapping format. In accordance with the dted 2 specification, the terrain elevation data have been edited to portray water bodies that meet minimum. Click on yellow tiles to download their corresponding data. To see how to tell the srtmdted has imported properly. All bodies of water with an axis greater than 1,200 meters for level 1 dted or greater than 600 meters for level 2 dted must be flattened. There are approximately 12,000 swbd files since only those srtm tiles that contain water have a corresponding swbd shapefile. This interface attempts to ease the pain of downloading 30meter resolution elevation data from the shuttle radar topography mission click on yellow tiles to download their corresponding data tiles come as zipped srtmhgt files at 1arcsecond resolution 3601x3601 pixels in a latitudelongitude projection, downloaded from nasa servers. Vertical accuracy of the srtm dted level 1 of crete. If a tile crosses two utm zones, it is delivered in both zones.
Dted2 was then aggregated into 3 arcsecond dted1 data. Scope basis of this document is the performance specification digital terrain elevation data dted dma, 1996 provided by the national imaging and mapping agency nima. With a special plugin, we can easily download the online srtm data directly from qgis. Browse other questions tagged data download dted or ask your own question. All oceans and sea elevations are set to zero and in falconview the area is colored blue. The horizontal datum is the world geodetic system 1984 wgs84 and the vertical datum is mean sea level as determined by the wgs84 earth gravitational model egm 96 geoid tr8350. This interface attempts to ease the pain of downloading 30meter resolution elevation data from the shuttle radar topography mission click on yellow tiles to download their corresponding data tiles come as zipped srtmhgt files at 1arcsecond resolution 3601x3601 pixels in a latitudelongitude projection, downloaded from nasa. Earthexplorer offers srtm data with a regularly spaced grid of elevation points in three file formats. The digital elevation models dem derived from the srtmxsar data are provided in the dtedformat. The following images show rendered images of the same area at resolutions ranging from 90 meters srtm dted, level 1 down to 3 meter usgs national elevation database and give an idea as to what information the different terrain resolutions provide. The usgs chart below shows morgan lake in new mexico. Dted data is available at three different resolutions, which are referred to as level 0, level 1 and level 2. It is generated by collecting elevation points of terrain. Dted level 2 corresponds to medium to large scale hardcopy products, and has a post spacing of.
If you download files one at a time, you can get dted or geotiff in. The global 1arcsecond 30m srtm digital elevation model is free and made available publicly a through the united states geological surveys earthexplorer site. Usgs eros archive digital elevation shuttle radar topography. Description z, refvec dted returns all of the elevation data in a dted file as a regular data grid, z, with elevations in meters.
Bookmark url global change master directory gcmd nasa. This is a simple python script, that uses dted 1 files from the srtm project 2, to find out the height in meters of a location on earth. Srtm dted1 is a uniform matrix of elevation values spaced 3 apart srtm dted, 2004. In accordance with the dted 2 specification, the terrain elevation data have. The dem represents ground surface topography, and excludes vegetation features. Digital elevation shuttle radar topography mission srtm usgs. The collections are located under the digital elevation category below the srtm subcategory. Other 3dep products are nationally seamless dems in resolutions of, 1, and 2 arc seconds. Nima used this topographic data from the 11day shuttle radar topography mission srtm for multiple applications, from developing navigation tools and supporting military operations, to geological and environmental purposes. We dont have to do hectic work like this as webgis provides us with readymade digital elevation data. Here is some data that i downloaded from usgs in a format that is usable in atak its all of north, central and south america and the caribbean, except for brazil. Shuttle radar topography mission dted level 1 3arc. The dma later changed its name to national imagery and mapping agency nima but is now called the national geospatial intelligence agency nga.
Version 2 includes dem data for australasia and small islands in the atlantic. Dted digital terrain elevation data is a military specification derived from srtm. Voidfilled srtm plus released srtm nasa v3 nasa has released a voidfilled version of the shuttle radar topography mission digital elevation model, known as srtm plus or srtm nasa version 3. Downloading satellite data from usgs websites youtube. Dted or digital terrain elevation data is a standard of digital datasets which consists of a matrix of terrain elevation values, i. There is an easier way to download srtm data on qgis. The military format specification milprf89020b for the digital terrain elevation data dted is available in a multitude of locations, including the nga reference site and at the usgs which publishes some srtm data in dted format the dted level 0 data is relatively small, and is often published as a concatenation of large area or global tiles in other than dted format, at. This video shows how to import or dted or srtm into atak. Gdp and the map of the world mow download nga products plugin. Version 2 is the result of a substantial editing effort by the national geospatial intelligence agency and exhibits welldefined water bodies and coastlines and the absence of spikes and wells single pixel errors.
Dted level 2 corresponds to medium to large scale hardcopy products, and has a. Dted level 2 corresponds to medium to large scale hardcopy products, and has a post spacing of one arcsecond, or 30 meter nominal resolution. Srtm dted level 1 values are derived from the srtm dted 2. Global multiresolution terrain elevation data 2010. Usgs, 2006b, shuttle radar topography mission dted level 1 3arc. The horizontal datum is the world geodetic system 1984 wgs84 and the vertical datum is mean sea level as determined by the wgs84 earth gravitational model egm 96 geoid. Srtm dted level 2 1 arc second data for the united states and territotial slands is.
Paraschouvertical accuracy of the srtm dted level 1 of crete. In this video ive explained how to download satellite data i. Vertical accuracy assessment for srtm and aster digital. Ocean, lake and river shorelines were identified and delineated from the 1 arcsecond dted2 data for details see nasa 2003 and were saved as vectors in esri 3d shapefile format esri 1998. Dted level 1 corresponds to medium scale hardcopy products, and has a post spacing of three arcseconds, or 100 meter nominal resolution. This standard was originally developed in the 1970s to support aircraft radar simulation and prediction. Digital terrain elevation data dted is a standard mapping format designed by the nga. Vertical accuracy assessment for srtm and aster digital elevation models.
The digital elevation models dem derived from the srtm xsar data are provided in the dted format. Each dted file contains elevation data for a 1 degree latitude by 1 degree longitude cell. At the time, srtm helped generate the most complete highresolution digital topographic database on earth. The elevation data are with respect to the reflective surface, which may be. Swbd is equivalent to srtm dted 2 20 m circular error, 90% confidence.
Srtm plus uses srtm version 2 see below where the radar interferometric method was successful not void. Dted level 2 is the basic high resolution elevation data source for all military activities and systems that require landform, slope, elevation, andor terrain roughness in a digital format. Tiles come as zipped srtmhgt files at 1arcsecond resolution 3601x3601 pixels in a latitude. On a uservalue level the dted data seems to be closer to bare ground data while srtm doesnt have the extra postprocessing.
Nasa has released version 2 of the shuttle radar topography mission digital topographic data also known as the finished version. Srtm consisted of a specially modified radar system that flew on board the space. Gtopo30 was derived from eight raster and vector sources of varying degrees of quality with processing techniques differing from continent to continent gesch and larson, 1998. The purpose of this specification is to assure uniformity of treatment among all mapping and charting elements engaged in a coordinated production and maintenance program for this product. The overflow blog how to develop a defensive plan for your opensource software project. Srtm is the treetop elevation, while dted is the ground.
Shuttle radar topography mission dted level 1 3arc second data dted1. Dted level 2 is a uniform gridded matrix of terrain elevation values with post spacing of one arc second approximately 30 meters. The srtm water body data files are a byproduct of the data editing performed by the national geospatialintelligence agency nga to produce the finished srtm digital terrain elevation data level 2 dtedr 2. Following a lengthy calibration and validation phase the 9 terabytes of raw data were processed continent by continent into digital topographic maps, and the last data set was delivered to nga in january, 2003.
Terrain elevations are described as the height above the earth gravitational model 1996 egm96 geoid, not the. Webgis is where you can find all the leading information and resources for geographical information systems. For example to find the height of the german zugspitze you need. Srtm dted is a uniform matrix of elevation values indexed to specific points on the ground.
This script is only a quick hack and i cant give any warranties. The onemeter dem is the highest resolution standard dem offered in the 3dep product suite. The srtm digital elevation data, produced by nasa originally, is a major. The absolute vertical accuracy requirement for swbd is equivalent to srtm dted 2 16 m linear error, 90% confidence. This function reads the dted elevation files, which generally have file names ending in. Dted files digital terrain elevation data what it is. The digital elevation model dem and the corresponding height error map hem are. Digital elevation model is a 3d representation of a terrain.
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