LiDAR

with position and orientation data it yields precise three-dimensional information about shape and surface characteristics. An instrument is principally a laser, a scanner and a specialised GPS receiver, and the returns form a dense point cloud whose points each carry three-dimensional coordinates, from which elevation, canopy, building and contour models are derived. The cited source describes airborne survey use, distinguishing topographic lidar with a near-infrared laser from bathymetric lidar using water-penetrating green light; it does not address robot navigation, sensor range specifications or laser safety classification.