How and why does police radar work?
Almost all the world's police forces use radar for measuring speed, enforcing speed
limits and collecting revenue. Ever since it was invented, anti radar measures have followed
close behind. Unfortunately, the police operate with 2 aces - they can pick the time and location
to make the most of the hunter's advantage of surprise ( and increase the kill ratio by choosing
places most people speed, whether or not it is dangerous) and the most effective active counter-measures
such as jamming and anti radar missiles are illegal. Radar works by sending out pulse or a
continuous signal of radio waves and listening for the reflection. When the pulse hits a
moving object, it's frequency changes, the exact amount of change depends on the speed of the
object and the direction it is traveling in. There is also a new system out that uses laser
light to measure speed. There are 3 main frequency areas that police radar works in, generically
known as X band (11 GHz), K band (24 GHz) and Ka band (32- 36 GHz). Find more on this subject here.
How does laser detection work?
LIDAR (light detection and ranging) is different from conventional radar in that it
uses laser light (frequency around 900 nm) to detect the vehicle speed and measures
the distance from the gun to the target several times. From the change in distance,
it can calculate the speed. As it measures distance, it is important that the gun is
held very steady to get an accurate reading, and the usual target in this case is the number
plate which is easy to see and a good reflector. This is important because the gun
relies on the reflections from the target to calculate the speed. From the drivers
point of view, what makes it different from radar is that it is very hard to detect. The
beam width is only around 4 feet wide at half a mile and there is very little scatter for
the detector to pick up. All LIDAR guns are also "instant on" where it locks on (almost)
instantly on the target when the trigger is pulled and is not left running constantly like
some radar guns. Find more on this subject here.
What should I do if I get pulled over?
You should always remain calm, roll down your window and wait for the police officer
to come to your window. If it is nighttime, turn on your interior dome light. This
helps to illuminate the inside of your car and lets the officer know you have nothing
to hide. Keep both your hands on the steering wheel, and don't make any sudden or
suspicious movements. Do not reach for the glove compartment or under your seat unless
directed to. Keep in mind, the officer has no idea who or what you are or may have
just done. Most officers prefer (or they should prefer) that you stay in your car
when you are stopped. If they want you to get out, they will ask you to. From an
officer's standpoint, many criminals will exit their car to try to prevent the officer
from seeing what they have in there with them.
The most important thing is your attitude. Remember, the officer generally has the
last word on traffic stops and you will do yourself no favors by irritating him/her.
That does not mean you have to suck up to them or anything, just be as courteous and
respectful as you can be and let it go at that. Let the officer do the talking, and most
importantly, don't admit to anything.
Other considerations if you are pulled over at night are to be prepared to be blinded.
Nighttime car stops are not the favorite thing for an officer to do. The officer will
likely utilize every light source available on the front of the patrol car. This can
be a bit overwhelming for the violator, especially if they are not expecting it. Today's
lightbars are with very bright "take-down" lights and modern halogen headlights, so your
mirrors can become a sea of brilliant white light in a split second. Just be prepared
for this and remember, the officer is at a significant disadvantage as it is, the lights
are just for his/her safety, not to offend you. Be polite, adjust your mirrors if you
need to, and let the officer do what they have to do.
Do not be offended by the flashlight. A flashlight is an officer's eyes at night, the
beam will move around quite a bit as he/she looks around in the dark, to
include the interior of cars. If, while an officer is scanning the interior of your
car for anything unusual, the beam of the flashlight happens to blast your retinas,
do not automatically assume that the officer did it intentionally. Also, remember
that the officer WILL look around inside your vehicle for safety reasons, so do not
be offended. Again, put yourself in the officer's shoes (or boots).