Speed Detection Systems
A speed detection device (often called a radar gun) sends out either a
microwave signal or beam of light. When this signal reaches its target,
part of the signal is reflected or bounced back toward the emitting gun.
The time required for the signal to leave the gun, bounce off an object,
and return is used to determine a vehicle’s distance and speed.
Radar
Radar (Radio Detection and Ranging) is a microwave system for
detecting the speed of moving objects by reflected pulses of high
frequency radio waves. There are 3 radar bands (microwave frequencies):
Xband (10.49 to 10.56GHz), Kband (24.04 to 24.26GHz), and the
“superwide” Ka band (33.4 GHz to 36 GHz).
The X band was the first used for traffic, followed by the K band which is
harder to detect (most instant-on radar is K band). The Ka band was
introduced in 1987, and widened to Ka SuperWideband in 1990 by the
FCC. The LRD 6299SWS/LRD 6399SWS monitors all current radar
bands including the entire Ka SuperWideband.
The radar beam is cone shaped — the narrower the beam, the greater the
resolution. A moving vehicle reflects radar signals back towards the radar
gun. The LRD 6299SWS/LRD 6399SWS can detect the signals emitted
by radar guns, and it will sound an audio alarm and flash a warning
indicator.
For continuously transmitting radar, use the LRD 6299SWS/LRD
6399SWS to get accurate detection from a safe distance. Weak signals
cause the audio and visual alarms to sound intermittently, but as the
signal gets stronger (the closer you get to the radar gun), both alarms
increase in intensity.
Instant-on transmitters fire a short radar pulse beam at a vehicle and
instantly read its speed. When detected at a distance, you will hear a few
beeps and see the strength meter begin to light. Instant-On radar signals
are the most difficult to detect at a safe distance because they are
transmitted only when directed at you or at a vehicle directly ahead of
you.
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