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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.
A digital elevation model ... (ASTER) instrument of the Terra satellite is also freely available for 99% of the globe, and represents elevation at 30 meter resolution.
Before the end of the same year, a 1-arc second global digital elevation model (30 meters) was released. Most parts of the world have been covered by this dataset ranging from 54°S to 60°N latitude except for the Middle East and North Africa area. [17] Missing coverage of the Middle East was completed in August 2015. [19]
Level 1 7.5-minute 30-minute Created by autocorrelation or manual profiling from aerial photographs May be derived from a wide variety of sources using any of a number of USGS approved techniques and instrumentation Level 2 All series Created from digital line graph (DLG) contours or equivalent, from any USGS map series up to 1:100000 scale
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 ...
In April 2008, the SWIR detectors of ASTER began malfunctioning and were publicly declared non-operational by NASA in January 2009. All SWIR data collected after 1 April 2008 has been marked as unusable. [2] The ASTER Global Digital Elevation Model (GDEM) is available at no charge to users worldwide via electronic download. [3]
The satellite images have pixel ground resolutions of under 0.5 meters, and overlapping images from different angles can be used to extract elevation data for DEMs. Based only on satellite position, there may be errors of several meters, but through ground control registration these can be reduced to point-to-point errors of 20 centimeters or ...
Includes different thematic maps such as: transportation, elevation, drainage, vegetation, administrative boundaries, land cover, population centres, and land use. Registration required. [2] FABDEM: The first global digital elevation model at 30 meter resolution with forests and buildings removed.