Basic Principles of Airborne LiDAR

May 09, 2023

Airborne lidar is an active detection technology that can accurately and quickly obtain three-dimensional space information on the ground or the atmosphere. It has a broad application range and development prospects. Previous sensors can only obtain the spatial plane information of the target, and need to obtain three-dimensional elevation information through technologies such as co-orbit and different-orbit overlapping imaging. Compared with LiDAR technology, these methods not only have low ranging accuracy, but also complex data processing. Because of this, LiDAR technology, together with imaging spectroscopy and synthetic aperture radar, is listed as the core information acquisition and processing technology in the Earth observation system plan. Airborne lidar is the product of combining laser technology, high-speed information processing technology, computer technology and other high and new technologies.

How Airborne LiDAR Works

LiDAR is a radar system, an active sensor whose data is in the form of a point cloud. Its working spectrum is between infrared and ultraviolet, and it is mainly composed of transmitter, receiver, measurement control and power supply. The working principle is: first emit a beam of laser light to the target to be measured, and then measure parameters such as the time when the reflected or scattered signal reaches the transmitter, the strength of the signal, and the frequency change, so as to determine the distance, speed and orientation of the target to be measured. In addition, it can also measure the dynamics of particles in the atmosphere that are invisible to the naked eye. The function of lidar is to accurately measure the position (distance and angle), shape (size) and state (speed, attitude) of the target, so as to achieve the purpose of detecting, identifying and tracking the target.