LICENSE PLATE RECOGNITION: Computer systems are able to capture the plate numbers of speeding cars and can use a flash or infrared camera to capture the image. Then the computer uses optical character recognition to establish the identifying number. After that the owner can be identified, or the plate checked against stolen cars, and any lawbreakers tagged. The techniques can work with stationary cameras or mobile units. Prototype systems were used in England starting in the nineteen eighties.
ANOTHER HIGH TECH WAY TO CATCH CROOKS: Another advanced technique uses a process called micro-X-ray fluorescence (MXRF), which rapidly reveals the elemental composition of a sample by shining a thin beam of X-rays onto it without disturbing the sample. All chemical elements emit and absorb radiation at a "signature" frequency of light. For instance, sodium emits primarily orange light, while oxygen (used in neon lights) emits green light. Scientists can pass collected light through an instrument called a spectrograph to spread it into a spectrum, much like visible light spreads into a rainbow of colors by a prism. By carefully studying how the spectrum becomes brighter or darker at each wavelength, scientists can tell what chemical elements are present in a given sample. MXRF can detect the sodium, potassium and chlorine from salts excreted in human sweat and left behind in detectable quantities in fingerprints. Since those salts are deposited along the ridge patterns in a fingerprint, it is possible to use the elemental analysis to produce a visual image of that fingerprint for analysis.
A SIMPLE WAY TO DISCOURAGE SPEEDERS: The Virginia Department of Transportation is placing optical speed bars at regular intervals along Lee Chapel Road in Springfield, a stretch of pavement notorious for fast driving and traffic accidents. The bars are about two feet long and a foot wide, and are placed at intervals that narrow from 24 feet at the start to 15 feet at the end. This creates an optical illusion -- a flip book effect -- that tricks speeding drivers into thinking they are driving faster than are, causing them to slow down. A British study has shown that optical speed bumps reduced fatal and serious injury crashes, and the method has already been successfully tested in Texas, Kansas and Mississippi.
The Institute of Electrical and Electronics Engineers, Inc.-USA, contributed to the information contained in the TV portion of this report.