Features of LiDAR system

LiDAR is a radar system that emits a laser beam to detect the position of a target. Its functions include searching and discovering the target; measuring its distance, speed, angular position and other motion parameters; measuring target reflectivity, cross section and shape and other characteristic parameters.

Depending on the scanning mechanism, LiDAR has two types: two-dimensional and three-dimensional. Most of them rely on rotating mirrors to emit laser light and measure distances by measuring the time difference between the emitted light and the light reflected from the obstacle surface. The reflector of the three-dimensional LiDAR is also pitched within a certain range to achieve the effect of surface scanning.

Two-dimensional LiDAR and three-dimensional LiDAR are widely used in advanced driver assistance systems. Compared with 3D LiDAR, 2D LiDAR only scans on one plane, with simple structure, fast ranging speed, stable and reliable system; but when 2D LiDAR is used in an environment with complex terrain and uneven road surface, it only scans on one plane. Single-line scanning can be performed on a plane, so data distortion and false reporting are inevitable. At the same time, due to the limited amount of data, a single two-dimensional LiDAR cannot be used to complete terrain reconstruction in an off-road environment.

Features of LiDAR

LiDAR uses laser as the carrier wave, which is electromagnetic radiation in the optical waveband, and the wavelength is much shorter than that of microwaves and millimeter waves. LiDAR has the following characteristics.

①Work around the clock without being restricted by day and night light conditions.

②The laser beam has a small divergence angle, concentrated energy, better resolution and sensitivity, and high detection accuracy.

③Information such as amplitude, frequency and phase can be obtained, and the Doppler frequency shift is large, which can detect targets from low speed to high speed.

④Strong anti-interference ability and good concealment. The laser is not interfered by radio waves and can penetrate the plasma sheath. When working at low elevation angles, it is insensitive to multipath effects on the ground.

⑤The laser radar has a short wavelength, can detect targets at the molecular weight level, and the structure size of the detection system can be made small.

⑥LiDAR has a three-dimensional modeling function and can detect all objects around 360°.