How does lidar calculate the speed of a vehicle?

Lidar calculates the speed of a vehicle by measuring the time it takes for emitted light pulses to travel to the vehicle and return to the lidar unit. This process is based on the principle of light reflecting off surfaces and returning to the source. When the lidar system emits a pulse of light, typically in the near-infrared spectrum, it travels to the target vehicle and reflects back. By calculating the time it takes for the light to complete this round trip, the system can determine the distance to the vehicle.

Furthermore, lidar typically sends out rapid sequences of light pulses to effectively track the movement of the vehicle over time. By comparing the distance measurements taken at different intervals, lidar can calculate the speed of the vehicle as it moves away from or toward the lidar unit. This precise measurement is effective in determining vehicle speeds accurately for law enforcement and traffic monitoring.

The other options do not accurately describe how lidar functions. Measuring weight and size or analyzing sound would not provide a reliable calculation of speed, nor would assessing fuel efficiency directly relate to speed measurements. Lidar’s unique ability to utilize light pulses for speed detection makes it a preferred choice for various applications, particularly in speed enforcement scenarios.