Uniden UNIDEN - Manual (Page 8)

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 three radar bands (microwave
frequencies): X-band (10.49 to 10.56GHz), K-band (24.04 to
24.26 GHz), and Ka-band (34.4 GHz to 34.8 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. The GPSRD
monitors all current radar bands including laser.
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 GPSRD 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 GPSRD 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.
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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