This video is of is a three-dimensional (3D) view of the Majuro Atoll, Republic of the Marshall Islands topobathymetric model which consists of topography (land elevation) and bathymetry (water depth). This video shows the importance of high-resolution, detailed topobathymetric models because the highest natural elevation for the Majuro Atoll is only three meters.
What is the projection, horizontal datum, vertical datum, and resolution for a USGS digital elevation model (DEM)?
Projection: 3DEP DEMS have different projections/coordinate systems depending on the product:
- 1/3-, 1-, and 2-arc-second (also the discontinued 1/9-arc-second) DEMs are not projected. They are all in geographic coordinates (latitude/longitude).
- 5-meter DEMs (Alaska only) are Alaska Albers Equal Area.
- 1-meter DEMs are in Universal Transverse Mercator (UTM).
- Original Product Resolution (OPR) DEMs – projection varies.
- The coordinate system and projection information for ALL DEMs are in each DEM file header; GIS software should detect them automatically.
Horizontal Datum: The North American Datum of 1983 (NAD83)
Vertical Datum: Typically the North American Vertical Datum of 1988 (NAVD88), although the National Geodetic Vertical Datum of 1929 (NGVD29) and local reference datums are used in some areas outside of the conterminous United States. For Hawaii, Puerto Rico, U.S. Virgin Islands, and Pacific Island territories, the vertical datum is typically referenced to local mean sea level.
Resolution: The conterminous United States is available at horizontal resolutions of
- 1-arc-second (~30 meters): full coverage
- 1/3-arc-second (~10 meters): full coverage
- 1/9-arc-second (~3 meters): partial coverage
- 1-meter: partial coverage
Learn more:
Related
How do I report errors in 3D Elevation Program (3DEP) elevation data?
If you think you’ve found an error in USGS elevation data, please send an email to tnm_help@usgs.gov. We will add the reported information to our "Digital Elevation Model Issues" data log for further analysis and possible correction. Spikes, pits, seam-line anomalies, and other data errors are of concern to us. We are working to correct or minimize known issues, but it will take some time. Errors...
What is the coverage of 3D Elevation Program (3DEP) DEMs?
Elevation products are summarized on our 3-D Elevation (3DEP) Products and Services website. View detailed availability maps (status graphics) through several sites: The National Map Download Client – Click “Show” below each elevation product Lidar Availability Viewer - Lidar point cloud only LidarExplorer – Lidar point cloud only DEM Availability Viewer - 1 meter DEMs only Learn more: What is...
What is the difference between lidar data and a digital elevation model (DEM)?
Light detection and ranging (lidar) data are collected from aircraft using sensors that detect the reflections of a pulsed laser beam. The reflections are recorded as millions of individual points, collectively called a “point cloud,” that represent the 3D positions of objects on the surface including buildings, vegetation, and the ground. Digital elevation models ( DEMs) are one of many products...
This video is of is a three-dimensional (3D) view of the Majuro Atoll, Republic of the Marshall Islands topobathymetric model which consists of topography (land elevation) and bathymetry (water depth). This video shows the importance of high-resolution, detailed topobathymetric models because the highest natural elevation for the Majuro Atoll is only three meters.
Monitoring the Earth's Landscape with Low-Cost High-Tech
by Rian Bogle, Remote Sensing Specialist
Monitoring the Earth's Landscape with Low-Cost High-Tech
by Rian Bogle, Remote Sensing Specialist
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Related
How do I report errors in 3D Elevation Program (3DEP) elevation data?
If you think you’ve found an error in USGS elevation data, please send an email to tnm_help@usgs.gov. We will add the reported information to our "Digital Elevation Model Issues" data log for further analysis and possible correction. Spikes, pits, seam-line anomalies, and other data errors are of concern to us. We are working to correct or minimize known issues, but it will take some time. Errors...
What is the coverage of 3D Elevation Program (3DEP) DEMs?
Elevation products are summarized on our 3-D Elevation (3DEP) Products and Services website. View detailed availability maps (status graphics) through several sites: The National Map Download Client – Click “Show” below each elevation product Lidar Availability Viewer - Lidar point cloud only LidarExplorer – Lidar point cloud only DEM Availability Viewer - 1 meter DEMs only Learn more: What is...
What is the difference between lidar data and a digital elevation model (DEM)?
Light detection and ranging (lidar) data are collected from aircraft using sensors that detect the reflections of a pulsed laser beam. The reflections are recorded as millions of individual points, collectively called a “point cloud,” that represent the 3D positions of objects on the surface including buildings, vegetation, and the ground. Digital elevation models ( DEMs) are one of many products...
This video is of is a three-dimensional (3D) view of the Majuro Atoll, Republic of the Marshall Islands topobathymetric model which consists of topography (land elevation) and bathymetry (water depth). This video shows the importance of high-resolution, detailed topobathymetric models because the highest natural elevation for the Majuro Atoll is only three meters.
This video is of is a three-dimensional (3D) view of the Majuro Atoll, Republic of the Marshall Islands topobathymetric model which consists of topography (land elevation) and bathymetry (water depth). This video shows the importance of high-resolution, detailed topobathymetric models because the highest natural elevation for the Majuro Atoll is only three meters.
Monitoring the Earth's Landscape with Low-Cost High-Tech
by Rian Bogle, Remote Sensing Specialist
Monitoring the Earth's Landscape with Low-Cost High-Tech
by Rian Bogle, Remote Sensing Specialist