Lidar is a radar system that emits a laser beam to detect target position, velocity, and other characteristic variables. Its working principle is to use a laser as the signal source, and the pulse laser emitted by the laser is scattered to trees, roads, bridges, and buildings on the ground through the swing of the laser scanning mirror. Part of the light waves are reflected onto the receiver of the LiDAR. By combining the height of the laser and the scanning angle of the laser, the coordinates of each ground point can be accurately calculated. By continuously scanning the target with pulsed laser, data on all target points on the target can be obtained. After imaging processing, accurate three-dimensional images can be obtained.

    Lidar is an advanced detection method that combines laser technology with modern optoelectronic detection technology. In addition to being used to obtain three-dimensional geographic information, it is also widely used in resource exploration, urban planning, agricultural development, water conservancy engineering, land use, environmental monitoring, transportation and communication, earthquake prevention and disaster reduction, unmanned driving and other fields. The working frequency of LiDAR is much higher than that of microwave, and it has the following advantages:

(1) High resolution

(2) Good concealment and strong resistance to active interference

Laser propagates in a straight line with good directionality and a narrow beam of light. It can only be received on its propagation path, so it is difficult for the other party to intercept. There are not many signal sources in nature that can interfere with LiDAR, so the ability to resist active interference is strong.

(3) Good low altitude detection performance

Due to the influence of various ground echoes, microwave radar has a certain blind spot in low altitude. For LiDAR, only the illuminated target will reflect, without any influence from ground echoes, and it can operate at zero altitude.

(4) Small size and light weight