Tranquil wrote:Can someone explain to me how these laser jammers function? Specifically how an off the shelf system has the processing power to interrogate the incoming optical wave, generate a return signal AND make the 'artificial' return arrive before the 'real' return. (thats physics defying stuff..).
A standoff method could be used (basically spamming), however its inefficient and the cops are going to see some fairly strange readings, which is sure to piss them off even more.
Here's a hint - one product's name is "Blinder"
The laser ranger and speed detection rely on the light reflected from the target back to the detector. The laser beam from the detector (about 1mW of infrared) spreads out to cover about a 2m circle at 1km (0.3mW/m^2). Some of this light gets reflected back towards the detector (say your licence plate (10cm x 30cm = 0.03m^2), about 9uW). This light spreads out as it gets back to the detector (say that power covers a cicle 10m in diameter at 1km), of which the LIDAR unit gets 9nW in total. If you have coherent-ish infrared light source, of about 10mW, focused in front of the car, that is likely to overwhelm the useful signal from the LIDAR unit, and probably blind it.
The LIDAR guns work best at night. They're not much use on a bright sunny day - there's too much infrared around. And rain and mist make them utterly useless.
Tranquil wrote:Fyi, the defeat mechanism of all Mil-Spec laser counter measure systems is simply LOS based, e.g Smoke and decoys. If the military are not using electronic methods to defeat laser rangers and trackers... Its safe to assume traffic 'laser jammers' are just another gimmick.
But you're not up against a milspec laser target designator, just a commercial LIDAR gun, which relies on the *tiny* amount of reflected light from your car. Overwelm the the sensor, the LIDAR can't read your speed or range.
