Picture
this scenario: You’re cruising down the
highway with your family, enjoying the lush greenery surrounding the open
road. A game of eye-spy is heating up as
you look around the landscape, trying to find a spot of yellow your daughter
has found on the road trip. Before you
know it, you spot a state trooper, his badge reflecting off the afternoon sun,
and a radar gun pointed directly at your vehicle. You panic, looking down at your speedometer; that’s
when you realize you’re doing a couple miles over the speed limit. Your hands clam up and before you know it,
POOF! You’re being pulled over.
So,
how exactly do these radar guns work? Well, “Radar” is an abbreviation for
Radio Detection and Ranging. Speed Trak
Police Radar can be found in almost every police vehicle. It’s estimated that 20 million speeding
citations are issued annually and that police radars are used in 13 million of
these cases.
Radar
Guns send out a signal of radio waves at specific frequencies in a specific
direction. Then, those waves bounce off
objects, including vehicles, and return to the radar gun’s receiving
station. When the waves reflect off a
moving vehicle, a measurable frequency shift, called Doppler Shift, occurs.
So,
police radar guns perceive a vehicle by transmitting a pulse that reaches the
target and then comes back to the observer.
What ensues is the Doppler Effect, in which the frequency of the pulse
is compared to the frequency of the reflection and speed is calculated using
the difference.
And…that’s
how it’s done! Had any crazy radar gun
experiences? Feel free to comment
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