Tuesday, July 24, 2007

Ever wonder how a police officer can ticket you for speeding if they are driving? Depending on the model Radar Gun they use, some models have a Moving Mode Radar. These units actually take two speed measurements to figure out your speed. The first measurement is to measure the ground echo, which is the measurement of the patrol vehicle. The second measurement is the target echo, or the speed of the target vehicle relative to the radargun. The difference between these two measurements is the actual target vehicle speed. Moving mode radar guns usually have an accuracy of +/- 2 mph. There are products on the market to help make moving mode police radarguns more accurate. Decatur makes a product called the Vehicle Information Portal for the Decatur SpeedTrak radar system. This unit plugs into the diagnostic port of the vehicle to read the actual patrol car speed through the vehicle’s computer. This unit works on cars manufactured after 1996 that use the OBD II diagnostics computer. Remember, just because the police car is driving in the opposite lane, doesn’t mean he can’t catch you speeding.

Ryan