Principle of laser imaging
3D laser Imagery with focal plan

Distance measurement using 3D LiDAR imagery is based on the time it takes for a wave to travel from its point of emission to an object, plus the time it takes to travel back to its acquisition point. Given that c is the speed of light, 299,792,458 m.s ^-1 (approximately 30 cm.ns ^–1 ), in air, measuring the travel time, Δt, enables us to directly deduce the object's distance R: R = c . Δt / 2.

This chapter describes the general physical principles of 3D laser imaging, and readers wishing to know more can refer to