NCJ Number
195005
Journal
Police: The Law Enforcement Magazine Volume: 26 Issue: 2 Dated: February 2002 Pages: 14-17
Date Published
February 2002
Length
4 pages
Annotation
This article describes the various devices available for speed enforcement by police.
Abstract
Digital radar is smaller and has increased targeting range and accuracy that results in better tracking history and conviction rates. Digital radar guns measure speed based on a 12-inch travel distance of target vehicles, compared to 10 to 15 car lengths used by analog guns. Target speeds with digital are immediate and can be recorded at great distances, up to two miles. Ka Band offers distinct advantages compared to X (10.525 GHz) and K band (24.150 GHz). These include smaller beam divergence and changing of frequencies within the band. Another detector defeating feature for Ka band radar, POP mode, is available. POP mode transmits for less than one-tenth of a second, and this extremely short transmission is outside of the sweep rate of radar detectors. But POP mode can only be used from a stationary position and it can’t be locked. Older analog radar guns always display the strongest reflected signal. Fast Vehicle Mode (FVM) displays the fastest vehicle in a group of approaching vehicles, not just the most reflective target. Operated in the stationary position, DSR-equipped radar guns show speeds in only one direction, selected by the officer, thereby eliminating target vehicle confusion. The use of lasers in speed enforcement is increasing, the guns are changing, and court precedents are being set. Laser speed guns have downsized and shed weight and their manufacturers have cut prices. They are now all-weather speed measurement tools. Laser jammers have entered the market because radar detectors with laser detection features have failed to provide any advanced warning to laser use. It is a felony to jam or attempt to jam a radar gun but there are no Federal sanctions. Photo enforcement has led to a dramatic reduction in traffic fatalities and injuries. Red light photo systems depend on trip mechanisms, imbedded road sensors, or laser beams that activate when the traffic signal turns red.