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Jamming the police radar: what else can we say?

Jamming Police Radar


In the Star Trek, the television series creator Gene Rodenberry introduced a device that made enemy spaceships “invisible” to the starship Enterprise.  Although the crew of the Enterprise knew roughly where the enemy spacecraft was, they couldn’t “see” it on their imaging devices.

Just imagine a device that could be used in automobiles so that cars would be “invisible” to police radar? Not that we are proposing that anyone break the law but wouldn’t it provide you with piece-of-mind if police couldn’t measure your speed? Let’s take a look at how police radar guns work.

Police radar guns emit bursts of radio waves at a frequency in the 1-8 Ghz range. The radio waves, traveling at the speed of light, bounce off of the target vehicle and return to the radar gun. At that point, a processing chip in the gun measures the time difference between the emitted and reflected waves and uses that to calculate the vehicle speed.  The result is highly accurate. For the police, they need to make sure he/she is pointing the gun at the correct vehicle. That’s not always easy to do.

Radar Jamming is the process of disabling a radar detector with “offensive technology.” It has been used for decades on military aircraft, boats and tanks.  Just recently, though, the technology has been migrated to the consumer world to jam police radar. The way it works is that the jammer, typically located on your dash, transmits radio waves that overpower the one shot by the police officer. The problem says Performance Dodge of Woodbury, NJ, a certified Chrysler, Dodge, Jeep, Ram dealer, is that using a radar jammer can be illegal in some states.

Wait did you say illegal? The Federal Communications Commission (FCC) regulates the frequencies used by radar guns. By law, it is a federal offense to broadcast using an unlicensed device on any police radar frequencies. The penalty is severe and can be up to $50,000 and/or five years in prison.  Not only is selling the devices illegal, it is illegal to even advertise radar jammers for sale.

There is another way that can be used to measure vehicle speed and that is with a laser gun. Police laser guns work on the same principle as radar guns, only the waves being transmitted are bursts of narrow beams of laser light.  Laser guns focus a beam of light down the road and the beam is so narrow that it can easily target one vehicle at a time. Like a radar gun, the laser gun waits to receive a light reflection off of its target and when it does, it can calculate how fast your car is going.  Interestingly, the FCC doesn’t regulate the light spectrum, that’s done by the Food and Drug Administration (FDA).

The operational goal of the laser jammer is to overwhelm the reflected light, causing the laser gun to register a faulty speed measurement, or no measurement at all. Laser jammers are triggered into action by a laser detector. Once activated, the jammer illuminates small banks of light emitting diodes or laser diodes that point back at the police laser gun. Humans can’t see the laser lights but the laser guns sure do.

While radar jammers are illegal in all 50 states due to federal law, laser jammers are regulated by states. Currently, these devices are legal in all states except California, Colorado, Illinois, Minnesota, Nebraska, Oklahoma, South Carolina, Tennessee, Virginia and Washington D.C.

Stealth Running

Unfortunately for speeders, the ability to have complete invisibility to police radar isn’t legal. As we mentioned above, it is legal to jam laser guns. Currently, limited invisibility is the best that speeders can hope for. This will undoubtedly change in the future as the technology continues to evolve and regulating laws change.


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