EA S

For speed cameras. It would have to be something that doesn't interfere with other things. Is it a big technical problem or could a simple one be made to operate on the right frequency? How expensive?

Probably illegal under communications and other laws, but just interested to know if it can be done.

discokin6

More to the point, I wonder if the Police have the proper certification to use these devices at the general public. I mean, with all the hoo har about Mobile Phones causing cancer and other claptrap, radars should be in the same boat.. And lasers, they'll cause permanant blindness if theyre shone in your eyes.

I've discussed this with a few mates of mine too. Its probably going to be MUCH easier to develop a device that tricks the radar into thinking youre doing some ungodly insane speed, like 800km/h than actually successfuly jamming the radar signals. Possibly combined with a radar detector, so it triggers off when youre actually being targeted.

Radar and laser speed traps take advantage of the doppler effect, listen to a V8 car driving past you. More to the point, listen to the engine note change just as it passes you. Anything emitting waves of anything that is moving is subject to the doppler effect. A radar speed device emits waves of a certain frequency. When it hits a car and bounces back, these waves become compressed. How compressed they are depends on how fast the vehicle is driving. So the more compressed they are, the faster the vehicle is going. If they aren't compressed, then the vehicle is stationary. So in order to dupe the radar device into thinking youre doing some insane speed, you just need to burst back some massively compressed microwaves. Then, when the copper pulls you over, you can claim his unit is busted, or his Daily Configuration Certificate is forged, etc.. Or that the flashless radar is out of order, how on earth can a Falcon do 800 km.h :D

BTW they use the doppler effect to judge how fast stars are moving away from us in astrophysics and other such intersting fields :)

Martin

How about painting you car in that paint thats applied to the F-117 and B2 Stealth aircraft, it absorbs the radar signal so it will look like the car isnt there to the radar operator. :s5

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discokin6

to work properly that requires perfectly flat panels :(

EA S

I've wondered about that, too, although there's so many sources of radiation of one sort or another it'd be near impossible to deduce from the real world. One possibility might be future workers' compensation claims from operators who get their gonads fried from continual exposure. Would there be enough output to put them at risk, particularly as most - maybe all - forms of radiation have a cumulative effect so that frequent exposure to even tiny doses can cause problems?

discokin6

yes, i'm a firm believer that non-ionizing radiation cannot do anyone harm, however circumstantial evidence is often cropping up that electromagnetic radiation can cause cancer, etc. Have you ever stood under one of those massive electricity pylons with a fluorescant tube in your hand? it lights up. scary. But then again, If I were in Victoria and I contracted cataracts, i'd be onto a lawyer quicksmart and sue the RTA for it.. I always wear sunglasses so it cant be from UV radiation.. Must be from all those pesky radars. Might even recoup some pocketmoney lost a few years ago, with interest :)

EA S

Apparently there's not a big risk of cancer from radar guns, but if it exists it's likely to be the testicular variety.

http://www.osha-slc.gov/SLTC/radiofr.../fnradpub.html

http://www.rcmp-learning.org/docs/ecdd0060.htm

Remember, boys, when you're not pointing it at a car, don't point it at your groin and don't sit with it in your lap.

discokin6

Or dont leave it sitting on the passenger seat :)


that second link is quite interesting too, I think it'll be in my best interests to join the force... 20% lower incidence.. you know, takin' care of business :D

EA S

Or it could be interpreted to show that cops are less well endowed than the general public and aren't smart enough to get out of the sun.

acekiwi

if the speed cameras work on radar why are there 3 sensors
built into the lane that the cam is facing and not the other side hmmmm