{"accessLevel": "public", "bureauCode": ["010:12"], "contactPoint": {"@type": "vcard:Contact", "fn": "U.S. Geological Survey - Core Science Systems", "hasEmail": "mailto:tnm_help@usgs.gov"}, "description": "To advance the U.S. Geological Survey 3D National Topography Model (3DNTM) including \n      \tthe next generation of the 3D Elevation Program (3DEP) and the 3D Hydrography Program (3DHP), \n      \tthe USGS researched and created a Seamless 1-meter resolution (S1M) Digital Elevation Model (DEM) \n      \tfor the conterminous United States (CONUS). This dataset is a result of a joint project between the \n      \tNational Geospatial Technical Operations Center (NGTOC) and the Earth Resources Observation \n      \tand Science Center (EROS) of the USGS National Geospatial Directorate (NGD). Scientists and \n      \tresource managers can use the S1M data for global change research, hydrologic modeling, \n      \tresource monitoring, mapping, visualization, and many other applications. A S1M DEM requires \n      \tmerging multiple lidar projects in which the lidar sensor, bare-earth DEM generation methodology, \n      \tsource resolution, datums/projection, unit of measure, and geoid (mean sea level model) can vary \n      \tbetween projects. This tile of the Seamless 1-m DEM was created from the best available \n      \t3DEP Original Product Resolution source DEMs from one or several intersecting 3DEP data \n      \tcollection projects. Spatially referenced metadata are contained within an open-source \n      \tGeoPackage that stores footprints for each of the input source DEMs along with source data \n      \tcharacteristics. The source DEMs were processed to align vertically to North American Vertical \n      \tDatum of 1988 (EPSG: 5703) updated to the current GEOID18 model and projected horizontally to \n      \tNorth American Datum of 1983 (2011) USA Contiguous Albers Equal Area Conic projection (EPSG: 6350). \n      \tHorizontal units and elevation values are in meters. Large data voids wider than 10 meters in \n      \tthe tile were backfilled with 1/9 arc-second or 1/3 arc-second DEMs in the 3DEP data repository \n      \twhile small data voids were interpolated across using bilinear interpolation. For tiles containing \n      \tmore than one 3DEP project or with large data voids, up to three blending routines were used: \n      \ta simple blend, narrow blend, or a backfill blend. The spatial metadata GeoPackage contains \n      \tinformation on where backfilling, void interpolation, and blending occurs within the tile. \n      \tThe tile spatial extent is 10 km x 10 km. The S1M DEM is available in a Cloud Optimized \n      \tGeoreferenced Tagged Image File Format (GeoTIFF). The S1M DEM has floating point numeric \n      \tvalues and a spatial resolution of one meter. NoData values (areas where data is incomplete \n      \tdue to lack of full data coverage) are represented with the numeric value of -999999. \n      \tOther 3DEP products are nationally seamless DEMs in resolutions of\n        1/3, 1, and 2 arc seconds. These seamless DEMs were referred to as the National Elevation\n        Dataset (NED) from about 2000 through 2015 at which time they became the seamless DEM layers\n        under the 3DEP program and the NED name and system were retired. Other 3DEP products include\n        project-based one-meter DEMs in CONUS, five-meter DEMs in Alaska as well as various \n        source datasets including the lidar point cloud and interferometric synthetic aperture \n        radar (Ifsar) digital surface models and intensity images. All 3DEP products are public domain. ", "distribution": [{"@type": "dcat:Distribution", "accessURL": "https://doi.org/10.5066/P13LJKFS", "description": "Landing page for access to the data", "format": "XML", "mediaType": "application/http", "title": "Digital Data"}, {"@type": "dcat:Distribution", "description": "The metadata original format", "downloadURL": "https://data.usgs.gov/datacatalog/metadata/USGS.4f34caac-f28f-4ea0-8d82-eafb2b8f9a5d.xml", "format": "XML", "mediaType": "text/xml", "title": "Original Metadata"}], "identifier": "http://datainventory.doi.gov/id/dataset/USGS_4f34caac-f28f-4ea0-8d82-eafb2b8f9a5d", "keyword": ["3D Elevation Program", "3D Elevation Program (3DEP)", "3D Hydrography Program (3DHP)", "3D National Topography Model (3DNTM)", "3DEP", "Bare Earth", "Cartography", "DEM", "Digital Elevation Model", "Digital Mapping", "Digital Terrain Model", "Elevation", "GIS", "Geodata", "Geographic Information System", "Grid", "High Resolution", "Hydro-Flattened", "Lidar", "Light Detection and Ranging", "Mapping", "National Elevation Dataset", "National Geospatial Directorate (NGD)", "National Geospatial Program (NGP)", "Raster", "S1M", "Seamless 1-m DEM", "Terrain Elevation", "Topographic Surface", "Topography", "U.S. Geological Survey", "US", "USGS:4f34caac-f28f-4ea0-8d82-eafb2b8f9a5d", "United States", "elevation", "geoscientificInformation"], "modified": "2026-02-25T00:00:00Z", "publisher": {"@type": "org:Organization", "name": "U.S. Geological Survey"}, "spatial": "-126.00, 24.00, -66.00, 50.00", "theme": ["geospatial"], "title": "Seamless 1 meter Digital Elevation Models (DEMs) - USGS National Map 3DEP Downloadable Data           Collection"}