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What data sources are used to produce the 3D Elevation Program (3DEP) DEMs?

The USGS 3D Elevation Program (3DEP) is in the process of collecting high-quality lidar and IfSAR (for Alaska) coverage for all of the United States and its territories. As this new data becomes available, legacy Digital Elevation Models (DEMs) are being systematically replaced with high-resolution DEMs produced almost entirely from the lidar and ifsar data.  

Legacy DEMs were produced from sources that include older lidar technology, cartographic contours derived from hand-drawn topographic maps, and Shuttle Radar Topography Mission (SRTM) elevation data.  

Learn more:   

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Digital elevation model created by an Unmanned Aerial System

What is a digital elevation model (DEM)?

A Digital Elevation Model (DEM) is a representation of the bare ground (bare earth) topographic surface of the Earth excluding trees, buildings, and any other surface objects.  DEMs are created from a variety of sources. USGS DEMs used to be derived primarily from topographic maps. Those are being systematically replaced with DEMs derived from high-resolution lidar and IfSAR (Alaska only) data...

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What is a digital elevation model (DEM)?

A Digital Elevation Model (DEM) is a representation of the bare ground (bare earth) topographic surface of the Earth excluding trees, buildings, and any other surface objects.  DEMs are created from a variety of sources. USGS DEMs used to be derived primarily from topographic maps. Those are being systematically replaced with DEMs derived from high-resolution lidar and IfSAR (Alaska only) data...

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small excerpt of Yosemite Valley topographic map in shades of green and brown

Why don't the elevations on your maps agree with those provided by my GPS system? Which are correct?

Elevations provided by your GPS receiver might disagree with elevations on a USGS map, but they could both be correct if they reference different vertical and/or horizontal datums. The default horizontal datum setting on most GPS receivers is the World Geodetic System of 1984 (WGS84) and the elevations are based on the NAD83 ellipsoid. USGS topographic maps published after 2009 are georeferenced...

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Why don't the elevations on your maps agree with those provided by my GPS system? Which are correct?

Elevations provided by your GPS receiver might disagree with elevations on a USGS map, but they could both be correct if they reference different vertical and/or horizontal datums. The default horizontal datum setting on most GPS receivers is the World Geodetic System of 1984 (WGS84) and the elevations are based on the NAD83 ellipsoid. USGS topographic maps published after 2009 are georeferenced...

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Lidar data of the Gulf Islands, Florida

What is the vertical accuracy of the 3D Elevation Program (3DEP) DEMs?

As of 2022, the absolute vertical accuracy of the 3D Elevation Program (3DEP) 1/3 arc-second seamless DEM product within the conterminous United States is approximately 0.82 meters root mean square error (RMSE), based on a comparison to almost 25,000 NOAA National Geodetic Survey OPUS points. Accuracy has improved from a RMSE of 1.55 meters tested in 2013, due to the addition of lidar projects...

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What is the vertical accuracy of the 3D Elevation Program (3DEP) DEMs?

As of 2022, the absolute vertical accuracy of the 3D Elevation Program (3DEP) 1/3 arc-second seamless DEM product within the conterminous United States is approximately 0.82 meters root mean square error (RMSE), based on a comparison to almost 25,000 NOAA National Geodetic Survey OPUS points. Accuracy has improved from a RMSE of 1.55 meters tested in 2013, due to the addition of lidar projects...

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Alaska IfSAR Elevation Image

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 –...

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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 –...

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excerpt of lidar imagery in Columbia Gorge

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...

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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...

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video thumbnail: Elevation link
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3D Elevation Program—Federal best practices

The goal of the 3D Elevation Program (3DEP) is to complete nationwide data acquisition in 8 years, by 2023, to provide the first-ever national baseline of consistent high-resolution three-dimensional data—including bare earth elevations and three-dimensional point clouds—collected in a timeframe of less than a decade. Successful implementation of 3DEP depends on partnerships and the development an
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Comparing methods used by the U.S. Geological Survey Coastal and Marine Geology Program for deriving shoreline position from lidar data

The U.S. Geological Survey Coastal and Marine Geology Program uses three methods to derive a datum-based, mean high water shoreline on open-ocean coasts from light detection and ranging (lidar) elevation surveys. This work compared the shorelines produced by the three methods for two different surveys: one survey with simple beach morphology, and one survey with complex beach morphology. For the s
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The 3D Elevation Program—Flood risk management

Flood-damage reduction in the United States has been a longstanding but elusive societal goal. The national strategy for reducing flood damage has shifted over recent decades from a focus on construction of flood-control dams and levee systems to a three-pronged strategy to (1) improve the design and operation of such structures, (2) provide more accurate and accessible flood forecasting, and (3)
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The National Map seamless digital elevation model specifications

This specification documents the requirements and standards used to produce the seamless elevation layers for The National Map of the United States. Seamless elevation data are available for the conterminous United States, Hawaii, Alaska, and the U.S. territories, in three different resolutions—1/3-arc-second, 1-arc-second, and 2-arc-second. These specifications include requirements and standards
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The 3D Elevation Program and America's infrastructure

Infrastructure—the physical framework of transportation, energy, communications, water supply, and other systems—and construction management—the overall planning, coordination, and control of a project from beginning to end—are critical to the Nation’s prosperity. The American Society of Civil Engineers has warned that, despite the importance of the Nation’s infrastructure, it is in fair to poor c
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3D Elevation Program—Virtual USA in 3D

The U.S. Geological Survey (USGS) 3D Elevation Program (3DEP) uses a laser system called ‘lidar’ (light detection and ranging) to create a virtual reality map of the Nation that is very accurate. 3D maps have many uses with new uses being discovered all the time.  
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1-Meter Digital Elevation Model specification

In January 2015, the U.S. Geological Survey National Geospatial Technical Operations Center began producing the 1-Meter Digital Elevation Model data product. This new product was developed to provide high resolution bare-earth digital elevation models from light detection and ranging (lidar) elevation data and other elevation data collected over the conterminous United States (lower 48 States), Ha
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Lidar base specification

In late 2009, a $14.3 million allocation from the American Recovery and Reinvestment Act (ARRA) for new light detection and ranging (lidar) elevation data acquisition prompted the U.S. Geological Survey (USGS) National Geospatial Program (NGP) to develop a common minimum specification for all lidar data acquired for The National Map. Released as a working draft in 2010 and formally published in 20
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The 3D Elevation Program initiative: a call for action

The 3D Elevation Program (3DEP) initiative is accelerating the rate of three-dimensional (3D) elevation data collection in response to a call for action to address a wide range of urgent needs nationwide. It began in 2012 with the recommendation to collect (1) high-quality light detection and ranging (lidar) data for the conterminous United States (CONUS), Hawaii, and the U.S. territories and (2)
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Accuracy assessment of the U.S. Geological Survey National Elevation Dataset, and comparison with other large-area elevation datasets: SRTM and ASTER

The National Elevation Dataset (NED) is the primary elevation data product produced and distributed by the U.S. Geological Survey. The NED provides seamless raster elevation data of the conterminous United States, Alaska, Hawaii, U.S. island territories, Mexico, and Canada. The NED is derived from diverse source datasets that are processed to a specification with consistent resolutions, coordinate
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USGS 3DEP Lidar Point Cloud Now Available as Amazon Public Dataset

The USGS 3D Elevation Program (3DEP) is excited to announce the availability of a new way to access and process lidar point cloud data from the 3DEP...

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USGS Topo Base Map Refreshed and Other Updates

The “USGS Topo Base Map” service named “USGS Topo” has been refreshed with new data and design changes. In addition, several of the “Data Availability...

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The 3D Elevation Program Distributing Lidar Data in LAZ Format

In support of ongoing efforts to provide efficient, cloud ready, open data formats for the use of lidar data, the USGS National Geospatial Program and...

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