What is the difference between lidar and millimeter wave radar

Lidar is a radar system that emits laser beams to detect the position, velocity and other characteristic quantities of targets. The millimeter wave radar refers to the radar that works in the millimeter wave band. Millimeter waves are essentially electromagnetic waves. The frequency band of millimeter wave is relatively special, its frequency is higher than radio, lower than visible light and infrared, and the frequency range is roughly 10GHz-200GHz.

Lidar

Concept: Lidar is a radar system that emits laser beams to detect the position, velocity and other characteristic quantities of targets.

Working principle: It transmits a detection signal (laser beam) to the target, and then compares the received signal (target echo) reflected from the target with the transmitted signal. After proper processing, the relevant information of the target can be obtained, such as Parameters such as target distance, bearing, altitude, speed, attitude, and even shape.

The advantage of the laser is that it has the advantages of wide detection range and high detection accuracy.

Technically speaking, the traditional lidar technology is quite mature at present, while the solid-state lidar and hybrid solid-state lidar are still in their infancy. Therefore, the lidars currently used by enterprises in autonomous vehicles are mostly mechanical lidars. With the rise of drone technology, there are now many advanced drone lidar on the market.

Millimeter wave radar

Concept: It refers to the radar whose working frequency band is in the millimeter wave frequency band.

Working principle: Millimeter wave radar principle: The electromagnetic wave signal emitted by the radar system is blocked by the object on its emission path and then reflected. By capturing the reflected signals, radar systems can determine the distance, velocity and angle of objects.

Millimeter-wave radar has been used in luxury cars since the last century, and the technology is relatively mature. The wavelength of millimeter wave is between centimeter wave and light wave, because this millimeter wave has the advantages of microwave and photoelectric guidance, and has the advantages of small size, light weight and high spatial resolution. Compared with lidar, the millimeter-wave seeker has better penetration ability to fog, smoke and dust.

The disadvantages of millimeter-wave radar are also intuitive. Its detection range is directly limited by the loss of the frequency band (if you want to detect far, you must use a high-frequency radar), it cannot sense pedestrians, and it cannot accurately simulate all surrounding obstacles.

Comparison of millimeter wave radar and lidar

1. The maximum distance of millimeter-wave radar is 1 km, while lidar is only 300 meters.

2. Millimeter-wave radar has general recognition ability, strong penetrating ability, and is not easily affected by the weather environment; Lidar has high accuracy and poor penetration, and is easily affected by dense fog, rain and snow.

3. The cost of radar is relatively high, but lidar is even higher.