Lidar is an active sensor used to obtain highly accurate and precise 3D measurements of surface locations

Lidar (Light Detection and Ranging) is an active sensor used to obtain highly accurate and precise three-dimensional (3D) measurements of surface locations in the form of point clouds, i.e., collections of points with associated locations in x,y,z space.

Lidar data of unpaved roads in Colorado’s Alamosa National Wildlife Refuge taken from a UAS-mounted lidar sensor (top). 

Data of a section of Colorado’s South Platte River collected from a lidar sensor mounted on a UAS (bottom).

Lidar sensors mounted on a low-altitude UAS platform collect surface elevations for ground positions sampled at regularly spaced horizontal intervals to generate high-resolution point clouds. These point clouds provide critical information about the Earth’s surface, such as light intensity/reflectivity, structural forest canopy metrics, structural heights, and bare-ground elevation.