Light Detection and Ranging (lidar) is a technology used to create high-resolution models of ground elevation with a vertical accuracy of 10 centimeters (4 inches). Lidar equipment, which includes a laser scanner, a Global Positioning System (GPS), and an Inertial Navigation System (INS), is typically mounted on a small aircraft. The laser scanner transmits brief pulses of light to the ground surface. Those pulses are reflected or scattered back and their travel time is used to calculate the distance between the laser scanner and the ground.
Lidar data is initially collected as a “point cloud” of individual points reflected from everything on the surface, including structures and vegetation. To produce a “bare earth” Digital Elevation Model (DEM), structures and vegetation are stripped away.
The USGS hopes to complete collection of lidar data for all of the U.S. and its territories by 2022 (status map). Due to high cloud cover and remote locations, Interferometric Synthetic Aperture Radar (IfSAR)—rather than lidar—is being used in Alaska.
The National Map is the primary repository for USGS base geospatial data. Access lidar data using:
- 3DEP LidarExplorer – Point cloud data and lidar-derived DEMs
- The National Map Download Client
- The National Map Services
Learn more:
Related Content
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...
What types of elevation datasets are available, what formats do they come in, and where can I download them?
Digital elevation data for the United States and its territories are available through The National Map Downloader. Click the “Help” link at the top of the page for detailed instructions on how to find and download data. There is a separate site for The National Map Services. The 3D Elevation Program (3DEP) products and services available through The National Map consist of standard digital...
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...
Related Content
- FAQ
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...
What types of elevation datasets are available, what formats do they come in, and where can I download them?
Digital elevation data for the United States and its territories are available through The National Map Downloader. Click the “Help” link at the top of the page for detailed instructions on how to find and download data. There is a separate site for The National Map Services. The 3D Elevation Program (3DEP) products and services available through The National Map consist of standard digital...
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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