Question: Will LIDAR penetrate a black windscreen?

[Lee]

LIDAR is infrared. Black absorbs heat. Hmmm...might be bad for me on my next LEO encounter, since my RADAR/LIDAR detector is directly behind my black windscreen. On the other hand, I can see a glowing light bulb, although faintly, through it.

Anyone know? Have experience with LIDAR that would be helpful?

Thanks,

Lee

[The GECCO]

Yes, it will penetrate. However, it should be noted that LIDAR, unlike RADAR is a VERY concentrated beam of energy and locks onto it's target in a matter of milliseconds. There aren't any "stray" energy waves out there that will set the detector off when the officer is clocking others in front of you. In other words, if your detector goes off and you are speeding you are pretty much cooked. The only reason to slow down is that you may as well pull over right away. At least he won't have to chase you so far and might give you a break for doing so.

I've seen tests in magazines where the gun is aimed at the license plate of a car (the preferred target) with a LIDAR detector mounted high on the windshield. The operator gets a solid lock and a speed reading and the detector never goes off. However, if the gun is aimed higher the detector goes off, but even if the driver full on stands on the brakes the gun still gets a good reading at the control speed the driver was told to go until the detector sounded. And this is in a controlled test where the driver is fully aware he is about to be clocked and has his foot hovering over the pedal waiting for the detector to alert. If you are cruising along and get hit, you'll NEVER be able to react fast enough.

I'm not saying it's pointless to have one (my Valentine 1 has it), just pointing out the limitations in case you or others were unaware.

Cheers!

[ZX12r_Pat]

What he said, great post Gecco.

Pat

[Lee]

Can I prove that instaneous hard braking worked? No. Did I beat 5 LIDAR traps? Yes.

I've never received a ticket because of LIDAR.

Lee

[onepoorstunna]

Can I prove that instaneous hard braking worked? No. Did I beat 5 LIDAR traps? Yes.

I've never received a ticket because of LIDAR.

Lee

Faster than a speeding bullet!

Let me try some basic calculations on this one, just for fun, can we? Lee is being oblivious, and Officer Joe triggers off a beam of light. Beam of light travels 400 yards in 0.000001220 of a second, and returns to the officer in another 0.000001220 of a second. Officers digital processing unit clicks along at something less than c itself, what with electron friction and all, returns a speed of XXX in (2 X 0.000001220 + ?) of a second.

Lee's reflexes, functioning at something of the normal humans, requires some 1/5th of a second from the moment his radar detector registers to BEGIN to lock the front wheel and "smoked" it. Actual deceleration itself requires WAY more than a second....so as best I can figure, unless the calculation time in the LIDAR unit requires more than 1/5 of a second, plus (2 * 0.000001220 ), Lee is hosed and his explanation of how he beats LIDAR ranks up there with the recent accident where apparently Lee believed someone locked the front wheel of his fast moving Busa and KEPT it that way for some multiple hundreds of feet?

You sure you beat LIDAR there Lee, and just didn't beat the cop to TRIGGERING the LIDAR? You see the officer, he reaches for his LIDAR, you reach for the brakes, somewhere during the braking the officer gets the gun working and by this time you are already below the posted limit? That means your reflexes beat the cops reflexes, you didn't beat LIDAR.....does that sound more reasonable or am I as wrong as I was about the guy on the Busa when I speculated that anyone locking the front and riding it that way at speed for a few hundred feet wouldn't work too well either?

[Lee]

Can I prove that instaneous hard braking worked? No. Did I beat 5 LIDAR traps? Yes.

I've never received a ticket because of LIDAR.

Lee

I'm an engineer and no stranger to exotic math, physics equations, and computers (I write software for a living.). Yes, light is pretty fast. But there are human beings operating LIDAR equipment and contrary to how fast you think the hand-held LIDAR unit performs its calculations, there are delays associated with it producing results. If you do you some more in-depth research, you will find that information.

Contrary to what everyone is led to believe, you can sometimes beat LIDAR. I am proof of that. How I did it is subject to speculation. The fact that I did it is not. I stand by my quoted statement, above: "Did I beat 5 LIDAR traps? Yes."

Who are you going to believe, me or what you read?

I think I'll believe myself and my experience. My point in posting this is that being hit by LIDAR is not always a "death sentence". In fact, if you are hit by LIDAR, do something and quickly. You might actually fail to be pulled over by an arresting officer.

If you do some further research, you will also discover that it is relatively difficult to successfully target a motorcycle with LIDAR until it is comparitively closer than a car of truck would be. Furthermore, LIDAR sends infrared (heat) and I have wondered if having both of my headlamps on, like small hot suns, could through sheer amplitude, overpower and interfere with a lased infrared signal. I have no definitive information on that subject yet. This analogy reminds me of how difficult it is to pick up satellite radio signals from the Earth when the satellite is between the Earth and the Sun.

Lee

[Lee]

You see the officer, he reaches for his LIDAR, you reach for the brakes, somewhere during the braking the officer gets the gun working and by this time you are already below the posted limit?

We also seem to have a slight misunderstanding. I did NOT see the officer and brake. I was being lased and had an alert BEFORE I braked.

I know that doesn't fit your paradigm so believe whatever you want.

Lee

[Lee]

This is from an interchange ZX12r_Pat and I had on the Southern Forum:
_______________________________________

Lee:
This is the best tutorial on this subject I have ever seen.
The tutorial is targeted (pardon the choice of word) towards drivers and how they can beat and/or defeat LIDAR.
http://www.mr2.com/TEXT/FAQonLidar.html
Lee

ZX12r_Pat:
Hey Lee,
Just a couple of things, that article is about 11 years old.So a lot of the information that I read in there is obsolete.I have first hand knowledge that LIDAR's range is about 3,000 feet and not 800 as the article points out.Also Colorado has given the laser judicial notice.
Pat
PS Good read though.

Lee:
Pat,
I have had 5 encounters with LIDAR. In 4 of them, I was significantly speeding: 1 - car, 3 - motorcycle (an FJR-1300).
In all 3 motorcycle incidents, I was the only vehicle on the road. Why was I not cited? My only defensive reaction was (and has been for years) to clamp down as fast and hard on the brakes as I possibly could.
In your professional opinion, why might I not have been cited for speeding?
Lee

ZX12r_Pat:
Because its very hard to get a reading on a motorcycle with LIDAR.Realize that the LIDAR unit works with a single beam that NEEDS to be reflected back to the unit.The motorcycle does not have much of a reflecting surface if looked at it from the front.The LIDAR needs to be held very still for the time it takes the unit to do its calculations.If it takes a lot of time to find an area that would reflect, the officer will get tired. By the time the LIDAR gets the speed, the speeder would have obviously had enough time to slow.
Regards,
Pat

Lee:
That is good news.
LIDAR uses a frequency of infrared - "heat" in the vernacular.
Would the heat generated from motorcycle headlights make the headlight reflectors less than a good reflector of the LIDAR beam? Would the heat the headlights generate interfere with a useful LIDAR beam reflection back to the officer?

=============

The officer, Pat, ultimately replied to my last question and said he didn't know the answer to it. I am thinking because LIDAR is infrared and has such low strength signals, a strong infrared source like bright headlights might interfere with its operation.

Also, as Pat said, if the unit has to be held still for a little while to perform its calculations. If a person were decelerating hard, that might show multiple readings and confuse the unit and/ or the officer.

I don't know these things for sure; they are just my best guesses at this point in time and I'm just sharing information.

Best regards,

Lee

[Mother Goose]

We should all just build stealth bikes and we won't have to worry about it :P