Escort ZR3. Well I read the tests and the warnings. Unit detects laser at the level where the cops aim at (Below windshild). When laser is fired at the front plate area V-1 won't even pick up the beam cause it is only 18 inches wide at 500 ft and 36 inches wide at 1000feet. ZR3 is an amazing laser detector. Note however that when it detects laser the cop already has your speed reading on his unit(return of beam happens in less than a second). Could not get the shifters to set off another laser detector, could not get the shifters to keep a Bushnel laser range finder from finding the exact range. Escort ee's said that it was due to Bushnell using 905 nanos vs. cops 904 nanos wave light wavelength. If cops only use 904 then why did Escort unit and V-1 unit detect laser fired from Bushnel using a 905 Frequency? Feeling like I got a faster way to know when to pull over, not a shifter/jammer, and a $700 lesson . Hopeing to get a friendly sheriff with a laser unit to help me do further testing.

 

so your saying that it doesn't jam the laser the cops are using? I got a little confused while reading you thread..but I was looking into the shifter as well? can you elaborate a little more? thanx

-tim

 

Don't know if it does or does not jam the cops laser's. It does not defeat a hand held Bushnel Range finder Laser using 905 nanos light wavelengths although it detects the Bushnel laser. It does not fire back a detectable laser of its own. I need proof from someones speed enforcment laser device that this thing actualy works.

 

you should post in the NY forum, I'm someone in that forum has a friend that's a cop

 

I'm not too familiar with real lasers, but from what I know they are true single-wavelength emitters. That means that a 904nm laser emits only light at 904nm, with no "spread" into other parts of the spectrum.

The odd thing to me is that the receiver in the ZR3 would have such a narrow bandwidth. Being tuned to only receive 904nm and reject 905nm sounds like quite a feat. If it's sophisticated enough I guess they could be using digital signal processing, which would allow them to tell the difference between the two, so maybe there's some truth to their story.

If that's the case, then your 905nm range finder fails to trigger the ZR3, so it does not respond with a jamming signal. I think the idea is to only respond to real police laser hits, so that they can't detect your jammer. That would also be why the cops use a unique wavelength, so your range finder can't be used to jam their stuff.

.

 

The Zr3 picks up the 905 wavelength Bushnell rangefinder it just can not defeat it. I get an instant range finding. Zr3 locates its sensors at lisence plate level and will pick up a laser fired below the windshild which is where the laser guns get fired at. Zr3 is an great laser detector, problem is that when it goes off cop already has your speed. (.3-.7 of a second return to gun)

 

Do police lasers detect speed using multiple distance calulations or do they detect doppler shift?

If the police laser makes multiple distance measurements, then you'd have to defeat it with a signal of the same freguency, but at a different time (distance = time). If the police laser uses doppler shift, you'd have to defeat it by returning a laser shifted in frequency enough to fool the police laser.

I think that normal radar guns detect dopler shift.

Also - light from a laser travels at more or less 186,000 miles per second, so the laser will travel from the cop car to you & back in quite a bit less than .3 seconds. Closer to .000003 seconds.

Hmmm.... seems like they use time, not doppler shift.

http://auto.howstuffworks.com/question396.htm



I thought that laser detectors worked by catching stray laser light from the cop hitting the car ahead of you? As you've pointed out, if the beam you, you are already caught, unless you can somehow disrupt their laser.

--Mike

 

Better yet -

http://www.mr2.com/TEXT/FAQonLidar.html

It's old, but interesting.

According to that source, the key is to reduce your reflectivity. You need to reflect less light back to the police, so that the reflected light is not strong enough to be detected by the originating laser.

--Mike

 

So having a SPA yellow metalic paint job is a problem. Next car will be dark. Marco you hear that!

 

Flat black. Painted with KMart spray cans.