Lurker Posted April 25 Report Share Posted April 25 Several digital elevation model (DEM) sources are used in the processing of Landsat Collection 2 Level-1 products. These sources are based on specific geographic regions and contribute to improved vertical accuracy in Collection 2 when compared to data processed in the past. Together, these sources are all known as the Landsat Collection 2 DEM. These DEM sources have been modified for use in Collection 2 processing; void filling techniques were used where persistent gaps were found in the elevation data, and improvements to the vertical accuracy were realized by differencing accuracies of other elevation datasets to the newer Collection 2 DEM. The following DEM sources are now available for download from EarthExplorer, listed under the Collection 2 section on the Data Set tab: Global Land Survey (GLS) — Various specific elevation inputs collectively make up the Global Land Surveys (GLS) DEM. Each input is based on the spatial region for which it is appropriate. Radarsat Antarctic Mapping Project (RAMP) — The Radarsat Antarctic Mapping Project (RAMP) is a high-resolution DEM that combines topographic data from a variety of sources to provide consistent coverage of all of Antarctica. Gravity for Earth, Ocean and Ice Dynamics (GEOID) Model — While not an actual elevation dataset, the geoid model provides necessary offsets to adjust the elevations of the GLS DEM from its original Earth Gravitational Model 96 (EGM96) to the World Geodetic System 84 (WGS84) ellipsoid. This is necessary so the GLS DEM can be correctly used by the Landsat processing systems software and algorithms. Please visit Landsat Collection 2 Digital Elevation Model to learn more about these DEM source products, and contact USGS Customer Services with any questions. links: Landsat Collection 2 DEM Source Products Available | U.S. Geological Survey (usgs.gov) Quote Link to comment Share on other sites More sharing options...
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