Can LiDAR see underground?
Verdict summary
No. LiDAR cannot see underground; it measures the ground surface. Its power is seeing the bare earth under trees and brush, which reveals foundations, mounds, old roads, mine dumps and earthworks that are hidden by vegetation.
Laser pulses from an aircraft pass through gaps in the canopy, and the returns from the ground are used to build a bare-earth model. Buried objects are only visible if they changed the surface shape.
Ground-penetrating radar and magnetometry are the tools that look below the surface.
Sources: USGS 3D Elevation Program (3DEP).
What is LiDAR used for in archaeology? Archaeologists use LiDAR to map ancient sites hidden under forest: it revealed thousands of Maya structures in Guatemala, ancient cities around Angkor in Cambodia, and Roman roads in Britain. It shows earthworks, walls, terraces and roads as shapes in the bare ground surface.
How can I see what used to be on my land? Look at historic maps and aerial photos of the spot. In the United States, USGS historical topographic maps go back to the 1880s and show buildings, mines, roads and schools; historic aerial photos go back to the 1930s or 1940s in many places; and fire-insurance (Sanborn) maps cover towns. Old county plat maps and deeds name past owners.
Primary sources cited
- USGS 3D Elevation Program (3DEP)