What principle does LIDAR utilize to calculate the speed of a vehicle?

LIDAR calculates the speed of a vehicle based on the time delay principle. By emitting a light pulse towards a moving vehicle and measuring the time it takes for that pulse to travel to the vehicle and back, the device can determine distance. When this process is repeated rapidly, if the vehicle is moving, the distance measurements will change over time. By calculating the difference in distance over the time it takes for the light to return, LIDAR can accurately determine the speed of the vehicle.

This time delay is critical in allowing LIDAR systems to perform precise measurements. The faster the vehicle moves, the shorter the time delay between successive measurements, which then correlates to a higher speed calculation.