Police Laser Gun Jammer
#17
Originally Posted by leedav
Just a thought... they spent all those billions on stealth fighters with composite radar absorbent and deflecting materials when they could have bought the Phazer II. Damn!
#18
Still plays with cars.
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Joined: Jul 2001
Posts: 15,078
Likes: 256
From: Montreal
Radar jammers for the military have been around for a long time, they call them ECM or electronic counter measures. Stealth is a passive technolgy.
Lidar effectiveness can be diminished by turning on headlights which emit light in the infrared spectrum too. To effectively jam lidar you would need a lot of power since you don't know the exact source. An array of hi power IR leds might do it ...
Lidar effectiveness can be diminished by turning on headlights which emit light in the infrared spectrum too. To effectively jam lidar you would need a lot of power since you don't know the exact source. An array of hi power IR leds might do it ...
#19
There was an article about 6 months ago in Automobile magazine by a cop called "how to speed". His advice for LIDAR was remove the front plate (the fine and points will be less for the equipment violation) and don't wash your car.
#20
Originally Posted by red996
http://www.blinder.net/ Does anyone have a Blinder M-20 E-Treme? I am thinking of getting one.
The ZR3 effectively difuses lazer and coupled with my V-1, I feel more secure than if I didn't have it! And i figure that if it works once, it is cheaper than the ticket with insurance increase!
I have read that the Blinder has additional coverage with a couple of different laser guns (which aren't used here), but I opted for the Escort name.
#21
After a couple drinks one night with an off-duty deputy we tested my Escort SRX laser jammer - IT WORKED!! Hands down these DO work and I proved it...However, was it worth $1200 with installation? Debatable.
#22
Drinking and driving with Johnny Law, interesting...... The srx does work on diffusing laser and it can plug up directly to the new passport x80 portable radar/laser detector if you already have one. Radar jammers do not work at all, notwithstanding they are illegal.
#23
Originally Posted by leedav
There was an article about 6 months ago in Automobile magazine by a cop called "how to speed". His advice for LIDAR was remove the front plate (the fine and points will be less for the equipment violation) and don't wash your car.
black, no front plate, no exposed headlights (most of the time), small overall frontal area with few flat surfaces.
#24
It is very important to make the distinction between laser and radar when you talk of jamming -- both with respect to effectiveness and legality.
It has been stated above that radar jamming is ineffective (not true) and that it is illegal (yes, true).
Radar jamming devices have come in two flavors -- active and passive. Since radar works on the doppler principle of wavelength shifting, knowing what frequency the speed measurement device is using would allow you to calculate the reflected frequency for any give velocity towards the speed measurement device. An active jammer would emit a signal at a greater amplitude (volume) than the reflected signal from the speed measurement device at the appropriate frequency to make the speed measurement device read an appropriate speed (let's say 55 MPH for instance). The speed measurement device will preferentially display the associated speed with the jammer's signal because it is read by the speed measurement device as a stronger (thus presumably more accurate) signal. Knowing this, it is possible to construct a device to emit this frequency at a high signal strength to "confuse" the measuring device time after time. But this is illegal at the federal level because signals of this frequency are regulated by the FCC which has strict rules on who is allowed to transmit (i.e. broadcast - as in a radio station or TV station) on them. This is done, presumably, to prevent mass mayhem from people using these frequencies to do things like broadcast their own "pirate" radio or TV stations.
The other type of device would be a passive radar jammer. These devices do not create and emit any signals at all. The principle by which they purported work is to modify the incoming signal by changing the way it is reflected back to the speed measurement device and thus make the speed measurement device read a lower speed. Unfortunately, it has been universally found that these devices are ineffective -- probably because it is not possible to modify the incoming signal precisely and consistantly enough and, more likely, because these manuvers (since they are passive) result in a lower amplitude signal being reflected back. The speed measurement device would then use the non-altered (and higher amplitude) reflected signal to read the actual speed of the vehicle. The good thing about these devices is that, since they are passive and not actually generating and transmitting a signal, they are perfectly legal to own and "operate". The down side is that they don't work. Thus Rocky Mountain is able to advertise the sell these passive jammers without interference from the FCC. Why they don't get nailed on false advertising claims, I'm not quite sure.
Switching gears entirely, as alluded to above, laser speed measurement devices are not regulated by the FCC but rather are in the medical laser frequency range and thus regulated by the FDA. There apparently is no FDA regulation against transmitting in this freqency when it doesn't relate to patient safety. Therefore, it is not federally illegal to create and transmit energy in this frequency range (I guess unless you are trying to package it as a patient care device). So active measures to confuse the laser speed measurement devices are perfectly legal on the federal level. Furthermore, since lasers work on essentially the same principle as radar as far as a doppler type frequency shift (just using a very different signal wavelength), active measures are effective in thwarting the speed measurement abilities of these devices. Unforunately, all is not hunky-dory with respect to the legality of owning and operating these devices as several states have gone beyond the federal regulations and made either the owning and/or operating of these devices in violation of state law. The list of states in which it is illegal to own and/or operate these devices is detailed in this thread:
https://rennlist.com/forums/showthre...hlight=blinder
Some testimonials as to the effectivenes of this class of devices are referenced in this thread on Renntech:
http://www.renntech.org/forums/index.php?showtopic=6000
Hope I was able to clarify and not further obfuscate.
David
It has been stated above that radar jamming is ineffective (not true) and that it is illegal (yes, true).
Radar jamming devices have come in two flavors -- active and passive. Since radar works on the doppler principle of wavelength shifting, knowing what frequency the speed measurement device is using would allow you to calculate the reflected frequency for any give velocity towards the speed measurement device. An active jammer would emit a signal at a greater amplitude (volume) than the reflected signal from the speed measurement device at the appropriate frequency to make the speed measurement device read an appropriate speed (let's say 55 MPH for instance). The speed measurement device will preferentially display the associated speed with the jammer's signal because it is read by the speed measurement device as a stronger (thus presumably more accurate) signal. Knowing this, it is possible to construct a device to emit this frequency at a high signal strength to "confuse" the measuring device time after time. But this is illegal at the federal level because signals of this frequency are regulated by the FCC which has strict rules on who is allowed to transmit (i.e. broadcast - as in a radio station or TV station) on them. This is done, presumably, to prevent mass mayhem from people using these frequencies to do things like broadcast their own "pirate" radio or TV stations.
The other type of device would be a passive radar jammer. These devices do not create and emit any signals at all. The principle by which they purported work is to modify the incoming signal by changing the way it is reflected back to the speed measurement device and thus make the speed measurement device read a lower speed. Unfortunately, it has been universally found that these devices are ineffective -- probably because it is not possible to modify the incoming signal precisely and consistantly enough and, more likely, because these manuvers (since they are passive) result in a lower amplitude signal being reflected back. The speed measurement device would then use the non-altered (and higher amplitude) reflected signal to read the actual speed of the vehicle. The good thing about these devices is that, since they are passive and not actually generating and transmitting a signal, they are perfectly legal to own and "operate". The down side is that they don't work. Thus Rocky Mountain is able to advertise the sell these passive jammers without interference from the FCC. Why they don't get nailed on false advertising claims, I'm not quite sure.
Switching gears entirely, as alluded to above, laser speed measurement devices are not regulated by the FCC but rather are in the medical laser frequency range and thus regulated by the FDA. There apparently is no FDA regulation against transmitting in this freqency when it doesn't relate to patient safety. Therefore, it is not federally illegal to create and transmit energy in this frequency range (I guess unless you are trying to package it as a patient care device). So active measures to confuse the laser speed measurement devices are perfectly legal on the federal level. Furthermore, since lasers work on essentially the same principle as radar as far as a doppler type frequency shift (just using a very different signal wavelength), active measures are effective in thwarting the speed measurement abilities of these devices. Unforunately, all is not hunky-dory with respect to the legality of owning and operating these devices as several states have gone beyond the federal regulations and made either the owning and/or operating of these devices in violation of state law. The list of states in which it is illegal to own and/or operate these devices is detailed in this thread:
https://rennlist.com/forums/showthre...hlight=blinder
Some testimonials as to the effectivenes of this class of devices are referenced in this thread on Renntech:
http://www.renntech.org/forums/index.php?showtopic=6000
Hope I was able to clarify and not further obfuscate.
David
#25
Phazer II is absolute BS! The M-20 (2 transponders) and M-40 (4 transponders) (and also the Escort ZR3 Shifter)Jammers are the real deal. They are so real that they are illegal in many places (some regulated by the FCC...Federalies). But if they're not illegal where you are they definately work. They can give you 5-20 seconds or reduce the distance of the laser guns effectiveness.
#28
Reputable(Blinder, Escort, K40, etc...) Lasers Jammers work, Passive Radar Jammers don't. Active Radar Jammers work but haven't been in production since KA Band began to be widely used.
#29
Furthermore, since lasers work on essentially the same principle as radar as far as a doppler type frequency shift (just using a very different signal wavelength), active measures are effective in thwarting the speed measurement abilities of these devices.
#30
Originally Posted by ebaker
I think lasers do not work on the doppler principle. They calculate target speed by repeatedly measuring the distance of the target from the laser. The speed is calculated from the change in distance per unit of time. The jammer transmits laser frequency garbage so that the change in target distance does not appear to be consistently changing.
You are exactly right. I went digging for the answer and found this explanation:
Laser (or lidar, for light detection and ranging) speed guns use a more direct method that relies on the reflection time of light rather than doppler shift. You have probably experienced the reflection time of sound waves in the form of an echo. For example, if you shout down a well or across a canyon, the sound takes a noticeable amount of time to reach the bottom of the well and travel back to your ear. Sound travels at something like 1,000 feet (300 meters) per second, so a deep well or a wide canyon creates a very apparent round-trip time for the sound.
A laser speed gun measures the round-trip time for light to reach a car and reflect back. Light from a laser speed gun moves a lot faster than sound -- about 984,000,000 feet per second (300,000,000 meters), or roughly 1 foot (30 cm) per nanosecond. A laser speed gun shoots a very short burst of infrared laser light and then waits for it to reflect off the vehicle. The gun counts the number of nanoseconds it takes for the round trip, and by dividing by 2 it can calculate the distance to the car. If the gun takes 1,000 samples per second, it can compare the change in distance between samples and calculate the speed of the car. By taking several hundred samples over the course of a third of a second or so, the accuracy can be very high.
Thanks for catching that. I've learned something new today too.
David