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2. Digital elevation model - Wikipedia

   en.wikipedia.org/wiki/Digital_elevation_model

   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 ...

3. Viewshed analysis - Wikipedia

   en.wikipedia.org/wiki/Viewshed_Analysis

   Viewshed analysis is a computational algorithm that delineates a viewshed, the area that is visible (on the base terrain surface) from a given location. It is a common part of the terrain analysis toolset found in most geographic information system (GIS) software. The analysis uses the elevation value of each cell of the digital elevation model ...

4. USGS DEM - Wikipedia

   en.wikipedia.org/wiki/USGS_DEM

   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 It has been superseded by the USGS's own SDTS format but the format remains popular due to large numbers of legacy files, self ...

5. Geographic information system - Wikipedia

   en.wikipedia.org/wiki/Geographic_Information_System

   A geographic information system ( GIS) consists of integrated computer hardware and software that store, manage, analyze, edit, output, and visualize geographic data. [1] [2] Much of this often happens within a spatial database, however, this is not essential to meet the definition of a GIS. [1] In a broader sense, one may consider such a ...

6. Triangulated irregular network - Wikipedia

   en.wikipedia.org/wiki/Triangulated_irregular_network

   In computer graphics, a triangulated irregular network ( TIN) [1] is a representation of a continuous surface consisting entirely of triangular facets (a triangle mesh ), used mainly as Discrete Global Grid in primary elevation modeling . The vertices of these triangles are created from field recorded spot elevations through a variety of means ...

7. DTED - Wikipedia

   en.wikipedia.org/wiki/DTED

   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 ...

8. Geomorphometry - Wikipedia

   en.wikipedia.org/wiki/Geomorphometry

   Geomorphometrics is the discipline based on the computational measures of the geometry, topography and shape of the Earth's horizons, and their temporal change. [2] This is a major component of geographic information systems (GIS) and other software tools for spatial analysis. In simple terms, geomorphometry aims at extracting (land) surface ...

9. GTOPO30 - Wikipedia

   en.wikipedia.org/wiki/GTOPO30

   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.