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brick
03-03-2005, 03:43 PM
What do you folks suppose would happen if one were to couple Veil with a reasonably powerful, constantly-transmitting IR source? It seems to me that it might be able to drown-out a weak return, reducing the targeting distance somewhat. I also suspect that the newer laser guns would eventually filter it out as if it were a hot-spot caused by bright sunlight and get a reading. (I also understand that some units have an error code that is set in similar circumstances.) Just a thought I had as I was staring at the walls of my cubicle today. Thoughts?

compu44
03-03-2005, 07:26 PM
would take a lot longer to get anywhere if it were on laser wavelength since everyone in front of you with a detector would be breaking.

brick
03-03-2005, 08:54 PM
Hadn't thought of that. But hey, if they all slow down and pull to the right...

JTW
04-05-2005, 08:40 AM
This theory was shown on "Myth Busters", the TV show and it didn't work. What they did was get 100 904nm LEDs, arranged them in a circle, and put it on the front of the car. The Stalker LZ1 did not get jammed.

Chris

antilaser
04-05-2005, 09:17 AM
Perphaps if you had the power of the sun installed in the front of your car, something like a thermonuclear reaction, it might be enough IR light power to saturate the lidar receiver and jamm the gun.
8)

happya$$
04-05-2005, 10:00 AM
Welcome to the forum Antilaser. Hopefully your product can give the Blinder (Michael Jordan of jammers) a good run for its money

Seven
04-05-2005, 08:16 PM
Well that blows my theory out the window! :)
What about those Nissan MPV's that have the IR camera upfront and cruise control? Every time they follow me they send my V1 crazy with laser alerts. Would they in any way interfere with Lidar?

This theory was shown on "Myth Busters", the TV show and it didn't work. What they did was get 100 904nm LEDs, arranged them in a circle, and put it on the front of the car. The Stalker LZ1 did not get jammed.

Chris

markos
06-19-2005, 10:44 PM
myth busters using LEDS` saw that made me sick ! there technical know-how is very limited you need to modulate the IR LEDs [like 1khz etc]

the RADAR tests were also very flawed ! telling us a microwave oven uses
the same freq etc etc...

a load of crappola

T-T
06-20-2005, 12:18 AM
Well that blows my theory out the window! :)
What about those Nissan MPV's that have the IR camera upfront and cruise control? Every time they follow me they send my V1 crazy with laser alerts. Would they in any way interfere with Lidar?


Yes, it has a "side effect" and Lidars can't measure these cars while the IR cruise control is on as I know.

markos
06-20-2005, 01:46 AM
A lot of cameras have IR leds they are not `ON` all the time they are
pusled so I geuss this would cause grief to LIDAR -real shame that

if the wavelenth is close to 900Nm and the rate is around 200pps sounds like
a plan...

designing my own reciever 1/2 done will post the info -

stalker
06-20-2005, 06:00 AM
ok, so if I got 50 904nm Ir LED,s and pulsed them say using a Radioshack kit that can do it then I would jam Laser???

Has anyone tried and has it worked....this is a test I would like to try....

Has anyone got some plans for a circuit board or anything....I wouldnt mind giving it a go but i havnt got a Laser to test it with.

markos
06-21-2005, 03:45 AM
I have used a 555 timer chip and a IR led to turn on my BEL945i
[If I had one that is]

Im studying the PRR of the various guns out there
200 to 300 seems to be the norm

most IR lighting kits sold for security are pulsed otherwise the leds would blow. the PRR you would have to measure -but `could` be a cheap way.
[damm sold my digital storage CRO]

there are cheap ones and there are ones with high output IR leds
these would be the one to aim for -then adjust the RC constant to get it
closed to 200-300

you could do it with IR LASERs and col lens`s also [like the blinders?]

my test RX unit so far can hear the suns hiss and fluro lights -im finding a 900Nm filter to get the bandwidth smaller -then some smarts to detect the 200 to 500 PRR [pulse rep rate] if thats what it uses.

m

stalker
06-21-2005, 05:03 AM
hmm...so u used a 555 timer kit and hooked Ir LEDs up to it?? Anyone got any design plans??? PM them to me if u dont want to post them

cheers

markos
06-21-2005, 06:48 PM
no just one led for testing my BEL945i
heaps of leds would require a power MOSFET etc. etc [A driver]

I see the stalker uses a 130 PRR and the pulse width is <30nsec
I think a fast swept pulse from 100 to 300 should do it mmm
Some have doppler audio so it cant be too slow -maybe I should
play my MP3 player through the diodes lots of crazy freqs -and I could say it`s for my IR headphones... [yes some IR headphones may hear the beam]

Grievre
06-22-2005, 04:09 AM
You actually need to pulse it a lot faster, around 1 MHz is good. At that speed, your jamming signal will get to the LIDAR before the light actually gets to your car :)

The laser will always read your range as between 0 and ~3 meters. As the range will confusingly jump around, there's no possible way the gun could get an accurate reading.

There are three things it could do:
1) Give a very low or negative speed reading
2) Have the speed reading fly around
3) Give an error reading

markos
06-22-2005, 05:04 AM
mmm-have to prove that one [1mhz]

I have just triggered my BEL with a LM3909 chip and an IR led @about 300hz -got about 3meters [no high power driver]

I will sweep the range to see the limits. [prr]

most of the `accross the door` IR beams are working in the KHZ and have col-optics. [might be also a cheap jammer] I have a few of these
from radio shack and you can hear the noise floor dissapear when you point it at my LASER rx unit.

I think returning a signal stronger and yet close to the original would be better. [for jamming] you can hear the doppler shift on some of the guns
so I geuss the operator would know if a 100 to 300 tone was sent back.

Something like 15khz might be better just out of the range of hearing. depends on the laser units bandpass filters. [dont know if 1mhz would get thru?] -and you would need very high spec IR/LAER diodes !

At the moment im just making a reciever not a jammer -
here in australia they will chase you down like a bank robber if you have a jammer ! [same as radar $2000 fine !!!!] -damm vg2

there is no easy way to actively finding a passive RX unit ! -except for when you slow down suddenly HA !

might use fibre optics to run to the front lights [old LAN stuff] because
of the high gain of the amplifier [less noise].

has anyone got a list of the PRR of the various LASER guns ?
And would be nice to know what freq the blinders work at.

m

stalker
06-22-2005, 05:35 AM
how will they tell u have a jammer?? once you slow down just switch it off and they will then get a reading...all is good.


VG2....they dont use that anymore.

markos
06-22-2005, 06:28 AM
if you are using an active jammer there machine will>

error out
doppler tones will be different
they will see the jammer unit thru the CRT/LCD viewfinder [maybe at night]
they are hiding in bushes and you suddenly slow down !

but a passive one hard to detect ans hard to find !

kpatz
06-22-2005, 06:49 AM
Laser doesn't use doppler tones... only radar does. Two totally different technologies.

I've toyed with using a 555 timer circuit and a IR LED or laser to create a laser detector tester. I'll never have the time to do it and my wife will think I've gone full mad scientist if I do. :twisted:

stalker
06-22-2005, 06:54 AM
haha you will have to show her your electron ;)

So what is the exact LED I will require for this?? Will I also have to run a resistor off the + side of the LED?? If so what value?

thanks guys, im keen to try this

markos
06-22-2005, 02:53 PM
the stalker uses "doppler type tracking tones"

do your research before you post !

kpatz
06-22-2005, 03:31 PM
the stalker uses "doppler type tracking tones"That's simulated doppler tones for LEOs used to using radar. Laser doesn't use doppler at all. The gun reads the speed, then it generates a fake "doppler tone" based on the measured speed. Only if the jammer causes random speed readings, and the gun relays those in the form of its "doppler type tracking tones", would jamming be detectable via the tones.