Under what condition will LIDAR measure the true speed of an object?

LIDAR systems are designed to measure the distance to an object by emitting a laser light pulse and analyzing the return signal. The true speed of an object can be accurately determined when it is moving directly toward or away from the LIDAR device. This alignment ensures that the detected changes in distance directly correlate to actual speed without the need for complicated calculations.

When an object is moving directly toward or away from the LIDAR sensor, the laser pulses sent out will return after reflecting off the object in a straightforward manner. This allows the LIDAR to measure the speed based strictly on the time it takes for the laser to travel to the object and back, providing an accurate velocity reading aligned along the path of motion.

In contrast, when an object is stationary, there is no speed to measure, and thus the LIDAR would register no movement. If the object is at an angle, this could lead to discrepancies between the measured distance and the actual path speed due to the cosine effect, resulting in an inaccurate speed reading. Lastly, while a constant speed is relevant for measuring speed, it is the direction of motion relative to the sensor that is critical, making the condition of direct motion the determining factor for accurately measuring true speed.