Tuesday, July 31, 2007

While all of these Doppler based radar systems use microwave emissions to perform their specific tasks, their designs are quite different.

Standard Police Radar Guns project a microwave beam in one direction only. There is no movement made by the antenna, and no cathode ray tube to display the information that the radargun “sees.” The only information you can get from a Traffic Radar Gun is how fast, and sometimes which direction. None of the police radars will tell you exactly which vehicle is traveling at the speed displayed on the unit.

Aircraft and weather radars rotate 360 degrees on their mounts sending out pulse patterns of microwaves. The signal retuned to the antenna can process the data from this signal to form not only a 2 or 3 dimensional picture of the object, but also determine the speed and direction in which the object is moving. This data is sent to a CRT monitor to display the picture that the Doppler Radar receives. This is useful to see cloud and weather patterns for the forecast. For aviation, it allows pilots and ground crews to know how many planes are in the air, exactly where they are, where they are going, and how fast they are moving. These radar units are very powerful, large, and extremely expensive. While they would be extremely useful to law enforcement, they would be detectable from great distances, and would be over the budget for most police departments.

Ryan