The Laser Ranging Sensor Beam Is Basically A Ray

The laser ranging sensor beam is basically a ray

After driving, when you are far away, the sound will be lower and lower. Why is this so? It turns out that the formation of sound is firstly due to the vibration of the sounding body, and then a sound wave that is dense and dense in the air around it is transmitted to the ear, causing the eardrum to vibrate with it, and people listen. It is the sound. The eardrum vibrates more often every second, and the laser ranging sensor feels a higher pitch; on the contrary, the eardrum vibrates less frequently per second, and the person feels that the pitch is low. In this way, what is the sound source, what we hear is what tune. The key to the problem is how the car moves. When the car arrives at a constant speed, the sound waves generated by the friction between the tire and the ground are “sparse”, “tight”, “sparse” and “closed”. They are arranged according to a certain law and at a certain distance. When the car is coming to you, it The "sparse" and "tight" sound waves in the air are pressed more tightly, and the problems of "sparse" and "dense" are closer. The pitch of the laser ranging sensor is higher. On the other hand, when the car is far away from you, it pulls the air in the air, the frequency of the sound is small, and the pitch is low. The higher the speed of the car, the greater the pitch change. In science, we call this phenomenon that the tone is different from the tone of the sound body, called the "Doppler effect." Interestingly, radar tachometers have been developed based on the principle of the Doppler effect. Since the laser beam is basically a ray, the estimated speed distance is far from the effective distance of the radar speed measurement, and can be measured outside 1000M; the speed measurement accuracy is high, and the error is <1 km; in view of the principle of laser speed measurement, the laser beam needs to aim perpendicular to the plane of the laser beam. The reflection point, because the distance of the vehicle under test is too far, and is in a moving state, or the plane of the vehicle body is not large, the work intensity of the duty police officer is very large and fatigue. Laser ranging sensors have produced laser speedometers with continuous automatic speed measurement that are specifically designed to solve this problem.