hittade dethär på wikipedia ang. lidar (
http://en.wikipedia.org/wiki/LIDAR)
Citat:
One situation where LIDAR has notable non-scientific application is in traffic speed law enforcement, for vehicle speed measurement, as a technology alternative to radar guns. The technology for this application is small enough to be mounted in a hand held camera "gun" and permits a particular vehicle's speed to be determined from a stream of traffic. Unlike RADAR which relies on doppler shifts to directly measure speed, police lidar relies on the principle of time-of-flight to calculate speed. The equivalent radar based systems are often not able to isolate particular vehicles from the traffic stream and are generally too large to be hand held. While there are distinct advantages to being able to pick out one vehicle in a pack, LIDAR has very serious problems associated with "sweep" error. Sweep error is almost always present because automobiles are typically targeted at distances ranging from several hundred feet to over one thousand feet. If the targets were flat surfaces moving forward, such as a large semi-tractor trailer truck, LIDAR can be more accurate. But, when the target is a jelly-bean-shaped automobile or SUV, sweep error is inevitable. Most traffic LIDAR systems send out a stream of approximately 100 pulses over the span of three-tenths of a second. A "black box," proprietary statistical algorithm picks and chooses which progressively shorter reflections to retain from the pulses over the short fraction of a second.
