Laser Radar: Hard to Beat

Welcome to science fiction, and a world where police use laser radar to track the speed of your car like the military uses lasers to supply a tracking mechanism for bombs and surgeons use for vision correction.

Knowing something about laser radar, however, can help you to not be caught speeding. Unlike regular band radar, which has a beam disbursement that makes the beam considerably wider the further it goes out, laser radar uses light compression technology to maintain the light in a very tight beam.

The term laser means Light Amplification by Stimulated Emissions of Radiation and most police units in use today are called either Light Detection And Ranging or Laser Detection And Ranging, with LIDAR being the most common acronym. These use pulsed light in laser radar to send out bursts of a light signal instead of a continuous microwave pulse.

What makes it so hard for detectors to locate the laser radar beam is the size of the circle that hits the vehicle. In regular radar, the beam may be reading the entire lane of the highway you’re driving on or even, if you’re far enough away, the entire side of the freeway. A dash-mounted detector is going to pick up on the signal.

Typical Detectors Out Of Light’s Sight

With laser radar, the beam is usually only about 18” when it hits your car growing considerably smaller the closer you are to the source. Since the beam is usually targeted to the front of the vehicle it’s normally aimed at a headlight, a part of the grill or some other reflective surface where your dash- or window-mounted detector is not going to pick up the signal. Add to that the fact that the laser radar issues a burst of light and not a continuous beam, and then even a cordless detector, which, by design, turns itself off and on to save battery power, may miss the beam if it does catch your front window.

There are laser radar detectors on the market that are mounted behind the grill and are fairly effective against laser radar, but they’re not the cheap radar detectors. Some of the higher-end laser radar detectors even emit a highly focused light back towards the source to “jam” the radar. Locating the detector heads is the key and the usually stealth configuration is to have one under each headlight and two in the middle of the grill.

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