Lidar Data for North Carolina: A Guide to the State's Elevation Data

USGS 3DEP serves lidar-derived elevation across North Carolina: 3.3 ft per pixel where a full-resolution lidar survey exists, about 9.8 ft per pixel where the model is built from older lidar. This guide explains what lidar is, how North Carolina was flown, what the data covers and how you can use it for contour maps, elevation profiles and 3D terrain models without specialist GIS software.

What is lidar?

Lidar stands for light detection and ranging. A scanner fires rapid laser pulses and times how long each one takes to come back. Combined with the aircraft's GPS position and an inertial measurement unit, every return can be placed precisely in three dimensions.

North Carolina's lidar is airborne: a scanner under a plane or helicopter sweeps the ground in overlapping strips. The result is a point cloud — millions or billions of points, each with an easting, a northing and an elevation, plus attributes such as return intensity and classification.

What makes lidar so valuable for terrain is that one pulse can produce several returns. The first may hit the crown of an oak or a loblolly pine; the last may reach the ground beneath it. Keeping only the ground returns gives a bare-earth digital elevation model (DEM) that shows the true shape of the land, even under the dense hardwood forest of the Blue Ridge.

North Carolina's lidar

North Carolina's statewide lidar is published through NC OneMap, the state's open geospatial data portal, run by the NC Center for Geographic Information and Analysis. The USGS 3DEP index records each lidar work unit with its name, year, quality level and cell size, and the coverage checker shows those for any address.

At the national level, the USGS 3D Elevation Program (3DEP) gathers lidar into one seamless bare-earth model of the United States, and it is the model every elevation on this site comes from.

Lidar coverage in North Carolina

Ground elevations on this site come from the USGS 3D Elevation Program (3DEP) seamless bare-earth model: 3.3 ft per pixel where a full-resolution lidar survey has been flown, about 9.8 ft per pixel where the model is built from older lidar, and about 33 ft per pixel elsewhere, with elevations above NAVD 88. The data is in the public domain. North Carolina’s statewide lidar is published through NC OneMap and carried by USGS 3DEP. USGS 3DEP serves lidar-derived elevation across North Carolina: 3.3 ft per pixel where a full-resolution lidar survey exists, about 9.8 ft per pixel where the model is built from older lidar. The work units differ in age and quality level, and the 3DEP index can list more than one for the same place. More from the USGS 3D Elevation Program and NC OneMap’s elevation data.

For any specific address, the lidar coverage page shows whether a lidar work unit covers it and which work units the index records there, with their year and quality level.

Accuracy and resolution

Vertical accuracy

Accuracy is inherited from the USGS 3DEP source and the lidar project behind it, not asserted by this tool. Where a full-resolution lidar survey exists the model is 3.3 ft per pixel and its vertical accuracy is that project’s, as USGS publishes it; where the model is built from older lidar it is about 9.8 ft per pixel; outside both the seamless DEM is about 33 ft per pixel and far coarser. The lidar coverage checker names the survey, its year and its quality level at any point, and every download states what share of its area fell outside the full-resolution lidar work units. Values are bare-earth elevations above NAVD 88 from a digital elevation model — they exclude buildings and tree canopy and are not a substitute for a surveyed elevation where a legal or engineering decision depends on it.

Quality level

The quality level is the USGS grade a survey was collected to: the specification its point spacing and vertical accuracy had to meet. It decides how much terrain detail survives under trees and how sharply small features such as ditches, curbs and retaining walls show. The 3DEP index records each work unit's quality level, and the coverage checker shows it for the point you search.

Ground classification

A raw point cloud contains returns from everything: trees, buildings, power lines, vehicles and the ground. Points are classified so the ground returns can be separated from everything above them. The ground returns become the bare-earth DEM, which is the only model this site reads.

DEM resolution

Where a full-resolution lidar survey exists, the 3DEP seamless model is 3.3 ft per pixel: each cell is 3.3 ft on a side. That is fine enough to show drainage ditches, terrace edges and individual landforms that disappear on coarser satellite-derived models.

How to get North Carolina lidar data

Option 1: raw data (for GIS professionals)

The National Map Downloader serves 3DEP DEM tiles and lidar point clouds (LAS/LAZ), and NC OneMap publishes the state's own lidar-derived elevation downloads on its elevation page. Working with the raw data takes:

• GIS software such as QGIS or ArcGIS Pro, or point-cloud tools for LAS/LAZ files;
• an understanding of coordinate systems and datums, because tiles, mosaics and your own data may each use a different projection and unit (metric or US feet);
• disk space and processing power, because point clouds are very large;
• tile management, because data is distributed as tiles that you download, merge and clip yourself.

Option 2: processed results in North Carolina Elevation Tools (for everyone)

Select an area on the map and choose what you want. You can:

• generate contour lines at any interval from 1 ft and download them as GeoJSON, DXF, PDF, KML or SVG;
• create elevation profiles for trails, rides and any line across the land;
• export 3D terrain models as STL or OBJ;
• download the DEM itself as a GeoTIFF;
• add elevation to GPX files and other GPS formats.

What you can do with lidar elevation data

Contour lines

Lidar supports contours at intervals far finer than those printed on published topographic maps, down to 1 ft — the detail needed for building pads, driveways and drainage.

Elevation profiles

Draw a line and read the ground along it. Hikers use profiles to judge a climb in the Black Mountains; engineers use them for roads, pipelines and fence lines.

3D terrain models

Turn any area into a printable model — Linville Gorge, Grandfather Mountain, or your own valley.

Flood and hazard work

Fine elevation data underpins flood modeling and landslide mapping. The NC Geological Survey publishes the state's landslide and geologic hazard mapping; this site's Water & Drainage tool shows where water would run and pond on the ground surface.

Land planning and building

Builders, architects and landowners use lidar to understand a site before design starts: earthwork, building pad placement, stormwater and views. It helps you prepare for a building permit conversation with the county planning department; it does not replace a survey where one is required.

Forestry and ecology

Because lidar measures both the ground and the canopy, it is used to map tree heights, streams, wetlands and erosion — useful across North Carolina's forest land, from the Blue Ridge to the Coastal Plain.

Lidar versus other elevation sources

Global satellite models cover the whole planet but at roughly 100 ft per cell or coarser, and many record the top of the forest rather than the ground. Good for a regional overview, not for site work.

Consumer GPS gives an altitude from satellite geometry or a barometer, and it is usually the least accurate part of a recorded track, especially in valleys and under forest.

Lidar (USGS 3DEP) gives true bare-earth elevation through vegetation at 3.3 ft per pixel where a full-resolution survey exists. For any serious terrain work in North Carolina it is the right source.

Using lidar without GIS software

Historically, using lidar meant specialist software, large downloads and a good grasp of projections. North Carolina Elevation Tools removes those steps. You do not need to:

• download gigabytes of point clouds or DEM tiles;
• install QGIS, ArcGIS or any other GIS software;
• understand coordinate systems, datums or metric-versus-feet units;
• manage tile indexes or merge datasets;
• run geoprocessing workflows.

Pick an area, choose the output and download it. That puts lidar within reach of hikers, landowners, students, architects and anyone else who needs accurate terrain information.

Licensing

USGS 3DEP elevation data is a U.S. Government work in the public domain: you may use it, including commercially. A credit to the USGS 3D Elevation Program is appreciated. Every file from Download Data carries the USGS credit.

Frequently asked questions

Related guides

• Contour lines for North Carolina — generate contour maps from lidar.
• Topographic maps of North Carolina — custom topo maps with lidar detail.
• Download DEM data for North Carolina — the elevation model itself.
• Hiking elevation profiles — profiles for trails and routes.
• Add elevation to GPX files — replace GPS altitude with lidar elevation.
• Download terrain as STL — 3D printable terrain from lidar.