Radar speed gun

<p>A radar speed gun, also known as a radar gun, speed gun, or speed trap gun, is a device used to measure the speed of moving objects. It is commonly used by <a href="/facts/Police/rrdGISgt">police</a> to check the speed of moving <a href="/facts/Vehicle/jSIEqANL">vehicles</a> while conducting <a href="/facts/Traffic_police/ucruFQIR">traffic enforcement</a>, and in <a href="/facts/Professional_sports/Tstj65ML">professional sports</a> to measure speeds such as those of <a href="/facts/Baseball/42bEQy1Y">baseball</a> <a href="/facts/Pitch_(baseball)/hqWRAtaq">pitches</a>, <a href="/facts/Tennis/GwVaWdn0">tennis</a> <a href="/facts/Serve_(tennis)/xKS5b2N8">serves</a>, and <a href="/facts/Cricket/tjuTASkU">cricket</a> <a href="/facts/Bowling_(cricket)/pztWTkkg">bowls</a>.
</p><p>A radar speed gun is a <a href="/facts/Doppler_radar/4a6nL2lA">Doppler radar</a> unit that may be handheld, vehicle-mounted, or static. It measures the speed of the objects at which it is pointed by detecting a change in frequency of the returned radar signal caused by the <a href="/facts/Doppler_effect/bzrK1BKf">Doppler effect</a>, whereby the frequency of the returned signal is increased in proportion to the object's speed of approach if the object is approaching, and lowered if the object is receding. Such devices are frequently used for <a href="/facts/Speed_limit_enforcement/c344ShSm">speed limit enforcement</a>, although more modern <a href="/facts/LIDAR_speed_gun/aLbsbxks">LIDAR speed gun</a> instruments, which use pulsed <a href="/facts/Laser/jk6PTvvT">laser</a> light instead of radar, began to replace radar guns during the first decade of the twenty-first century, because of limitations associated with small radar systems.
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Radar speed gun open-in-new

Radar speed gun