What is a LIDAR?

LIght Detection And Ranging (LIDAR) is a technique to measure the distance between the sensor, a laser source of light and an object. By precisly timing of the round trip return time of a pulse of light backscattered from the target, its location can be calculated. With a solid object, the return pulse of reflected light will be sharp. With a diffuse object, such as a forest canopy, there will be many return pulses reflected by different elements of the canopy. Using high speed and precise timing of the return pulse, information about the 'depth' effect can be determined. This is the basis of the LIDAR technique to study vegetation.