Laser jammers

[SpeedyBoy]

I can't resist the temptation to throw myself back into this fray to clarify that LaserVeil does NOTHING to prevent RADAR, hence the name LASERveil... and it works for me in the REAL world, so make up your own mind.

[avgas]

Not to be an arse, but diffraction has NO relavance in the matter of speed measuring using neither LIDAR nor RADAR. If you look at a surface the only relevance is the reflection and absorption characteristics - and reflection characteristics includes scattering (think mirror vs. a rough metal surface).

How do you think it is absorbed rather than reflected.....not everything hits a surface at 90 deg

[Mikkel]

How do you think it is absorbed rather than reflected.....not everything hits a surface at 90 deg

Absorption happens when the energy of the photon is spent in exciting valence electrons, in the atoms constituting the material, to a higher energy state. This excited state can undergo a wide range of internal conversions before returning to the ground state. Some of the more notable are: Vibrational energy (heat) and spontaneous emission (flourescence).

As for not everything hitting surfaces at normal incidence (90 deg) - a more correct statement would be that most doesn't. However, most surfaces are not flat and the light will under go scattering as it is reflected. If you signal is strong enough and has a large enough "spot size" there will be fairly strong signals scattered in almost every direction, which in turn may reflect and scatter of other surfaces. (i.e. the signal bounces around until it has all been absorbed or has left the atmosphere)

[ArcherWC]

most of the "guns" you see the plod holding are still radar, not laser.
I have literally had 1 laser pickup in the last two years and have done over 50,000 kays all over Auckland

[avgas]

energy of the photon is spent

I'm not going to continue this argument anymore, it is pointless for me to continue past this point. I will simply leave you with your quote, if you wish to continue this on your own - you can play your own devils advocate. And think of why i have used this quote.

[Winston001]

The RADAR fooling paint isn't something you just buy and definitely not for $40! It was layers and hollow sphere's inside that let the signal in then let it go at an angle that won't be picked up from the source direction.

Just searching around about jammers and found this thread.

So far as "stealth" paint is concerned, my understanding is that the US stealth bombers are painted in specific layers. The effect is to bounce the radar signal twice - a millisecond or so apart, and the two waves hit each other. Being the same frequency they then cancel each other out. Neat huh!

So....jammers aren't really an alternative to a good detector?

[Gremlin]

So....jammers aren't really an alternative to a good detector?

detection is useless with laser, it warns ya, and at the same point, you're nicked... so jamming (strawberry please) is your best bet for laser.

Radar... (bar instant on - you're nicked, believe me) you have that small chance... Really, I use it more like a game, get a warning, and see if you can spot him/her. When I've been naughty its barely made any difference to the outcome.

[CookMySock]

The effect is to bounce the radar signal twice - a millisecond or so apart, and the two waves hit each other. Being the same frequency they then cancel each other out.

An unlikely explanation. For the two signals to arrive back at the reciever 180 degrees out of phase, the two reflecting surfaces have to be half a wavelength apart - thats a few millimeters, and we are talking thousandths of a microsecond, not milliseconds.

So....jammers aren't really an alternative to a good detector?

yep. Or a good set of eyes - you can spot a cop car at the far end of a straight quite easily - a long time before he has a solid microwave lock on you.

DB

[Swoop]

So....jammers aren't really an alternative to a good detector?

Definately not.
Laser will have you instantly, without warning, unless you are in a line of traffic and the plod is good enought to zap a few others in the near vicinity.
A jammer will negate this threat.

Radar will require picking up signal at the longest range possible to be aware of the threat. Plod using the radar, even instant-on, on other vehicles up the road is the best detection. Use the best detector on the market that your wallet can get.

[marty]

At last count there was ONE laser in the whole Waikato, and from experience, it is a pain to use - the instant-on Stalker is much better, not to mention safer, as it is used from inside the car - it is just too dangerous to step out and stop cars travelling at high speed, and takes too much time to get in the car and give chase. Laser is really effective on passing lanes, or on an overbridge, but reality is it is not the weapon of choice. I did 50000kms last year, much of it on SH1 in the Waikato/South Auckland, and according to Mr Bell got pinged by laser once, by the Botanical Gardens at Manurewa. I got tracked by, or picked up signal of a Stalker, almost every day.

[Biggles2000]

actually what they do is design (i.e. shape) to dissolve the big wavelength (interhamonics) signals and coat to defract or reflect (depending on angles) the lazer signals so yes it does do both. But no i am not talking about that crap paint that you get. I'm more talking about military based designs that avoid detection.
Rumor has it the new lambo had an engineer specifically to see if he could integrate some of these concepts into the vehicle. I suspect that is all bullshit though.

No its not bullshit. I have a lotus and it is very small and low, made up of relatively low radar reflecting (soft) materials like fiber glass ans carbon fiber and has almost zero flat frontal surfaces. I know from experience that the police have a jolly difficult time getting the radar to lock onto it.

[Biggles2000]

I got a laser warning going into the Lyttleton tunnel, its the only one I have had in 18 months. I believe they were sitting in the tunnel control building pinging vehicles after the 100kph where it drops to 50kph

[Forest]

According to wikipedia, each B-2 stealth bomber costs about 550 million USD to manufacture.

Which makes me think that it would take a wee bit more than a coat of paint to make a vehicle invisible to laser & radar speed detectors.

[R6_kid:Me]

According to wikipedia, each B-2 stealth bomber costs about 550 million USD to manufacture.

Which makes me think that it would take a wee bit more than a coat of paint to make a vehicle invisible to laser & radar speed detectors.

Do some more research and you'll find that the surface of the B2 (and F-117) used a painted on substance to absorb the radar/laser waves/light. Technological development has since meant that it can be integrated into the panels rather than just being painted on (or it may be the other way around). There is a reason they dont fly in wet weather...

"The B-2 uses radar absorbent material and coatings that require climate-controlled hangars for maintenance.["

[CookMySock]

I have a lotus and it is very small and low, made up of relatively low radar reflecting (soft) materials like fiber glass ans carbon fiber and has almost zero flat frontal surfaces. I know from experience that the police have a jolly difficult time getting the radar to lock onto it.

Its hard to lock because simply because it presents a small frontal surface.

Doppler Radar will get a very good reflection on microwave-transparent items. We used to experiment with a Gunnplexor - it would get excellent doppler signals from plastic balls and rolled up tissue paper.

DB