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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.
USGS DEM – The USGS' Digital Elevation Model GTOPO30 – Large complete Earth elevation model at 30 arc seconds, delivered in the USGS DEM format; DTED – National Geospatial-Intelligence Agency (NGA)'s Digital Terrain Elevation Data, the military standard for elevation data; World file – Georeferencing a raster image file (e.g. JPEG, BMP)
Global Roads Open Access Data Set (gROADS) Well documented global dataset from NASA's Socioeconomic Data and Applications Center of roads between settlements using a consistent data model (UNSDI-T v.2) which is, to the extent possible, topologically integrated, and accurate to approximately 50m. Only roads between settlements are included, not ...
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 software stores 2-D grids as COARDS-compliant netCDF files and comes with a comprehensive collection of free GIS data, such as coast lines, rivers, political borders and coordinates of other geographic objects. Users convert further data (like satellite imagery and digital elevation models) from other sources and
Each pixel stores values, such as surface elevation data, for display in 3D computer graphics. A heightmap can be used in bump mapping to calculate where this 3D data would create shadow in a material, in displacement mapping to displace the actual geometric position of points over the textured surface, or for terrain where the heightmap is ...
Currently, the best source for nationwide LiDAR availability from public sources is the United States Interagency Elevation Inventory (USIEI). [1] The USIEI is a collaborative effort of NOAA and the U.S. Geological Survey, with contributions from the Federal Emergency Management Agency, the Natural Resources Conservation Service, the US Army Corps of Engineers, and the National Park Service.
A national lidar dataset refers to a high-resolution lidar dataset comprising most—and ideally all—of a nation's terrain. Datasets of this type typically meet specified quality standards and are publicly available for free (or at nominal cost) in one or more uniform formats from government or academic sources.