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A digital elevation model ( DEM) or digital surface model ( DSM) is a 3D computer graphics representation of elevation data to represent terrain or overlaying objects, commonly of a planet, moon, or asteroid. A "global DEM" refers to a discrete global grid. DEMs are used often in geographic information systems (GIS), and are the most common ...
The Shuttle Radar Topography Mission ( SRTM) is an international research effort that obtained digital elevation models on a near-global scale from 56°S to 60°N, [2] : 4820 to generate the most complete high-resolution digital topographic database of Earth prior to the release of the ASTER GDEM in 2009. SRTM consisted of a specially modified ...
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. This standard was originally developed in the 1970s to support aircraft radar simulation and prediction. Terrain elevations are described as the height above the Earth Gravitational ...
GTOPO30 is a digital elevation model for the world, developed by United States Geological Survey (USGS). It has a 30- arc second resolution (approximately 1 km), [1] and is split into 33 tiles stored in the USGS DEM file format . According to DTED and USGS DEM the absolute vertical accuracy of GTOP30 varies from ±30 meters.
On 29 June 2009, the Global Digital Elevation Model (GDEM) was released to the public. [8] [9] A joint operation between NASA and Japan's Ministry of Economy, Trade and Industry (METI), the Global Digital Elevation Model is the most complete mapping of the earth ever made, covering 99% of its surface. [10]
The National Elevation Dataset (NED) consists of high precision topography or ground surface elevation data ( digital elevation model) for the United States. It was maintained by the USGS and all the data is in the public domain. Since the 3D Elevation Program came online, the NED was subsumed [1] into The National Map as one of its layers of ...
The primary mission objective is the generation of WorldDEM, a consistent global Digital Elevation Model (DEM) with an unprecedented accuracy according to better than DTED Level 2 specifications. WorldDEM resolution will correspond to DTED Level 3 (post spacing of better than 12 meters) and a height accuracy of better than 2m (relative)- a ...
USGS DEM. The USGS DEM standard is a geospatial file format developed by the United States Geological Survey for storing a raster -based digital elevation model. It is an open standard, and is used throughout the world. It has been superseded by the USGS's own SDTS format but the format remains popular due to large numbers of legacy files, self ...