How does a laser speed gun work to measure a car's speed?
If you have read the article entitled How Radar Works, then you know how
normal radar works. A normal radar set sends out a radio pulse and waits for
the reflection. Then it measures the doppler shift in the signal and uses the
shift to determine the speed.
The new laser speed guns use a more direct method that relies on the
reflection time of light rather than doppler shift. You have probably
experienced the reflection time of sound wave