Radar gun
From Free net encyclopedia
Image:Radar gun.jpg A radar gun is a small Doppler radar used to detect the speed of objects. A radar gun does not return position or power information. It relies on the Doppler effect applied to a radar beam to measure the speed of objects it is pointed at.
Radar guns may be hand-held or vehicle-mounted. Common uses include traffic speed law enforcement and measuring speeds in sports.
Most of today's radar guns operate at X, K, Ka, and (in Europe) Ku bands. An alternative technology, LIDAR, uses pulsed laser light.
There are radar detectors on the market which can detect most of police radar and laser systems. Conversely, in the spirit of electronic warfare, some police radars are equipped with detectors of operating radar detectors.
How radar guns work
Radar guns are, in their most simple form, radio transmitters and receivers. They send out a radio signal, then receive the same signal back as it bounces off the objects. However, the radar beam is different when it comes back and from that difference the radar gun can calculate vehicle speed.
A radar beam is similar to the beam of a flashlight as it spreads out as the distance from the signal origin increases. The signal then bounces off objects in the path of the beam and are reflected back to the gun. The gun uses the doppler effect to calculate the speed of the object in the beam's path.
All bands of radar work the same, they simply operate on different frequencies. X band guns are becoming less common due to the fact the beam is strong and easily detectable. Also most automatic doors run radar using X band and can possibly affect the readings of police radar. As a result K band and Ka band are most commonly used by police agencies.
Problems with radar guns
Although radar is an effective tool to acquire an object's speed, there are problems with it. Today's technology is relatively effective and error free so most inaccurate speed measurements are caused by the user.
For speed to be accurately calculated the object whose speed is desired should be the only moving object in the beam of the radar. If this is not the case it is impossible to determine which object's speed the system is reading. The angle in which the object is in relation to the radar source can also affect the reading. This includes angles on a horizontal and vertical plane.
As a result of these errors many police agencies requiring accurate speed measurements are switching to LIDAR which is much more effective.
FACT- Radar guns are less likely to work in the morning.