Land records · Parcel maps · October 7, 2026
Lidar Elevation Data: How to Use It for Land
What lidar elevation data is: laser-scanned ground heights used to make detailed terrain models. How to find free lidar and use it to study property.
Lidar elevation data is information about ground and surface heights collected by lidar, which stands for light detection and ranging. Aircraft or drones send laser pulses toward the ground and measure how long they take to return, building a dense cloud of points. Processing removes trees and buildings to create a bare-earth digital elevation model showing the terrain in detail. Lidar is widely used for flood mapping, drainage studies, forestry, and engineering, and many states and counties offer it free online. This page is general land-records background, not legal advice.
Lidar products
| Product | Description |
|---|---|
| Point cloud | Raw laser returns with coordinates |
| Bare-earth DEM | Ground surface with vegetation removed |
| Surface model | Top of trees and buildings |
| Hillshade | Shaded relief image for visualization |
| Contours | Lines of equal elevation derived from the DEM |
Uses for property research
- Seeing slopes, ravines, and drainage paths.
- Estimating building sites and driveway routes.
- Identifying old roads, foundations, and stone walls hidden by trees.
- Studying floodplain relationships, though official flood determinations rely on FEMA maps and surveys.
Finding lidar
The USGS 3D Elevation Program provides national lidar coverage. State GIS offices and county viewers often host lidar hillshades and contours. See how to use a county GIS viewer.
Accuracy
Lidar vertical accuracy is often within several inches in open areas, less accurate in dense vegetation. It is excellent for planning but not a substitute for a surveyor’s measurements for design or legal purposes.
Datums
Lidar elevations reference a vertical datum, usually NAVD88. See what is a geodetic datum.
Lidar and flood elevations
Lidar helps estimate ground elevations relative to base flood elevations, but official elevation certificates require surveyed elevations.
Example
A buyer evaluates a wooded rural parcel using a county lidar hillshade. It shows a flat bench near the road, a steep ravine at the back, and a faint old logging road. This helps plan a house site and driveway before ordering a survey.
Change over time
Comparing lidar from different years can show erosion, fill, or new construction.
Viewing tools
Free GIS software and online viewers can display lidar hillshades, measure elevations, and create profiles.
Reading a hillshade
A hillshade shows terrain as if lit from one direction, usually the northwest. Ridges and slopes facing the light appear bright, and slopes facing away appear dark. Flat areas look smooth and gray. Linear features, such as old roads, ditches, and terraces, often stand out clearly. Because the lighting direction can make valleys look like ridges, check contours or elevation values to confirm what you see.
Lidar and archaeology
Lidar has revealed old stone walls, cellar holes, and abandoned roads in forests across New England and elsewhere. These features can help explain old deed calls and boundaries that follow walls or roads no longer in use.
Bottom line
Lidar elevation data uses laser scanning to map terrain in detail, producing bare-earth models, hillshades, and contours. It is valuable for studying slopes, drainage, and hidden features, but surveys are needed for design and legal work. Find free lidar through USGS and state GIS. Explore terrain and parcels via the Platbookmapper map.
Lidar elevation data FAQ
What is lidar?
Laser scanning that measures ground and surface heights.
Is lidar data free?
Much of it is, through USGS and state programs.
How accurate is lidar?
Often within several inches in open areas.
Can lidar replace a survey?
No, it is for planning, not legal measurements.
What is a bare-earth DEM?
A terrain model with trees and buildings removed.