Title: LiDAR Elevation Dataset – Bare Earth Digital Elevation Model (DEM)

Originator: USDA - NRCS - FPAC BC GEO


Light Detection and Ranging (LiDAR) is an optical remote sensing technology that measures properties of scattered light to find range and/or other information of a distant target. LiDAR is defined on a functional level as the integration of three technologies into a single system capable of acquiring data to produce accurate DEMs. The technologies are: lasers, Global Positioning System (GPS), and Inertial Navigation Systems. Combined, they allow a high degree of accuracy in the positioning of the footprint of a laser beam from a fixed wing aircraft as it hits objects on the earth’s surface.

“Digital Elevation Model (DEM) Whitepaper, NRCS High Resolution Elevation Data” calls for high-resolution elevation data at 1 to 5-meter posting for terrain mapping and conservation planning and analysis activities. Conventional DEM files consisting of terrain elevations for ground positions at regularly spaced horizontal intervals do not provide the level of accuracy needed to analyze small (1 to 2 ft) differences. LiDAR digital elevation data can be generated at a variety of resolutions. Currently NRCS and FPAC BC (Farm Production and Conservation Business Center) support the 3DEP the planning and investment of Quality Level 2 data or better LiDAR.  3DEP defines QL2 as 2-4 nominal point spacing with a vertical accuracy of 10 cm RMSE2.  The 3DEP planning and investment process helps NRCS and FPAC BC partner and collect the highest resolution available using airborne linear LiDAR sensors. NRCS and FPAC BC employees, users, and consumers maximize their return on investment by using LiDAR QL2 or better to implement the conservation planning and design of practices, farm bill program implementations, and analysis of natural resources applications.

FPAC BC uses available LiDAR data distributed by other agencies and partners that are public domain. The Geospatial Enterprise Operations (GEO) branch has a partnership with the USGS to share high resolution elevation data and to provision authoritative content to internal and external customers using map and data services.  To obtain information about high resolution elevation data and LiDAR data from the USGS National Map go here.

The 3D Elevation Program (3DEP) was established to promote the exchange of accurate digital land elevation data among government, private and nonprofit sectors, and the academic community and to establish standards and guidance that will benefit all users. For further information, see https://www.usgs.gov/3d-elevation-program  . The United States Interagency Elevation Inventory is maintained here and was developed to keep LiDAR customers up to date on what data are available and planned for acquisition

The USGS LiDAR Point Cloud (LPC) collection can be browsed here using the National Map Downloader. To see availability status, select the 'Custom Views' tab on the top left and select "Elevation" from the drop down menu, then scroll down in the table of contents to click "Show Availability".

USGS 3DEP Lidar Point Cloud Now Available as Amazon Public Dataset and for more information go here. 

GEO is evaluating the specifications, nominal pulse spacing and vertical accuracy of the LAS point clouds in the NRCS/FPAC BC Elevation Data Mart to determine which datasets will support the 1- and 2-meter bare earth raster digital elevation models. The order in which the high-resolution elevation data will be added to the service will be based on agency priorities and business requirements and from input from NRCS Customers at the State and Local Field Offices.

The LiDAR products provide high-resolution bare earth elevation data from which derivative products can be made, such as contours, hillshade, aspect and slope rasters. Conventional DEMs do not provide the level of accuracy needed to analyze small (1-2 foot) differences. LiDAR is an opportunity to take advantage of an extremely accurate and consistent base layer that will benefit agency business as well as the public. Some applications include: 
• Hydrologic modeling 
• Engineering surveys and planning 
• Floodplain delineations 
• Terrain visualization 
• Determination of slope gradient, aspect, and complexity 
• Fast and accurate stream cross-section acquisition and geomorphology mapping 
• Watershed evaluations 
• Wildfire planning, fire behavior modeling, and rehab 
• Oil and gas and mining rehab

The elevation units is meters. This is the same units as the map window and cell dimensions.

Format: GeoTIFF

Spatial Reference Information: Universal Transverse Mercator, North American Datum 1983

Sample LiDAR Elevation map