http://www.audiworld.com/news/03/lidatek/

Reprinted without permission from Audiworld. Please visit the link to see the orig. article and pics.


Lidatek LE-20 Laser Echo: Evening the Odds

Audiworld visited Lidatek to see laser technology firsthand, talk tech of laser, install a LE-20 and do some in the field testing with Lidatek's available sampling of laser guns.

How's that driving record of yours? Clean? No tickets? How about your car insurance? Are you in that "low risk" group because of that clean driving record? Let me guess... you never exceed the speed limit, right? Yea, that's what I thought.

If you live in an area where law enforcement uses laser guns for speed detection the odds of keeping that clean record are stacked in favor of the police. (By the way, did I mention the insurance industry partially funded laser gun development? Tickets equal higher insurance premiums.) Lidatek is here to help even out those odds with the LE-20.


Lidatek LE-20

We all know there's an unspoken rule that the police won't bother you if you're a few miles over the limit--they've generally got their eye out for the guy who's not playing by the rules. But, that unspoken rule varies depending on where you live and the mood of the officer that you encounter. You could be outside that particular officers acceptable margin or perhaps the officer is just in a foul mood and you "look" like you need to be stopped--you never know! If you use a radar detector and the police are using a radar gun chances are you know he's up ahead and have time to lift off the throttle a bit just so you're sure not to attract any attention to yourself--let the woman in the Taurus riding in your blind spot get the attention as you drop back.

But today, with the increasing use of laser based speed detection that luxury of lifting off the throttle to be sure you're within the acceptable margin has been all but removed. It's even worse if he's playing "dirty pool" and hiding hoping to ambush unsuspecting drivers--then, you don't have a chance against laser. Even if you have a detector that senses laser, because of the way laser guns work, generally all your detector will tell you is that you've been targeted and by then it's too late. Before your brain has time to tell your foot to lift off the throttle the officer knows your speed. Game over.


Laser: the odds are against you

The reason you have a fighting chance against radar guns is they spray a broad microwave beam at approaching traffic. That beam hits the traffic, some misses and shoots down the road, hits road signs and buildings--the microwave signal bounces all over the landscape. A radar detector picks up on the stray signals bouncing around and sounds a warning. If you have a good radar detector, under the right conditions, it can sense even the most evil radar, instant Ka, at ranges exceeding a mile away.

Laser on the other hand, is a small tight controlled beam of infrared light. At the distance an officer is likely to target a vehicle the laser beam is no larger than the front of an average car. The laser light does not bounce around like a microwave beam so there's very little, if any, stray signal to pick up.

Lidatek's LE-20 is a solution to odds imbalance. The LE-20 is a small transponder that is mounted on the front of the vehicle, usually near the front license plate, that sits and watches for the laser light pulses that laser guns use to measure vehicle speed. When it detects laser it returns a laser pulse for a short period of time with a 17 watt laser (100x more powerful than LED based units!) giving you time to check your speed and respond very much like you would with a radar detector.

The Science of No Speed

So how / why does this stuff work? Laser guns are very fast at obtaining a vehicles speed. Under the right conditions, a laser gun can get a speed reading in 1/3 of a second, but in real world use sometimes factors effect the guns ability to get a reading quickly. Simple factors like particulates in the air (remember we're dealing with light) or the officer not holding the gun steady can dramatically increase the time it takes to get a reading so it's not unusual for the laser gun to not get an immediate speed reading. Lidatek uses the real world delay to buy you some "stealth time" to check your speed and get into the speed margin.

The way a laser gun calculates a vehicle speed is by sending out short pulses of light (nanoseconds in duration) and watching for a return reflection of the beam from some reflective surface of the car (the license plate being the most desirable). Each time it sends/receives a pulse the gun calculates the distance to the vehicle based on the delay between the pulse and the time for the reflection to return. By taking lots of distance readings over a period of time the gun can calculate the speed of the vehicle. If the gun can't get repeated distance measurements that make sense it can't calculate the speed of the vehicle. In simple terms, the LE-20 varies the laser guns distance measurements.


17 watt laser emitter
(not actual emitter, representative sample shown for security reasons)

When the LE-20 sees laser pulses that match the profile of a laser gun it samples the pulses for a short time (nanoseconds) to determine the gun type and to synchronize it's own 17 watt laser pulses with the pulses from the laser gun, then it fires back. Laser guns watch for weak reflections of the transmitted pulse which is typically only about 10% of the light sent out by the laser gun. With the LE-20's laser synchronized, it sends out much stronger pulses back to the gun. Those pulses contain timing errors which result in distance calculation errors. With distance measurements that are all over the map the gun is unable to calculate vehicle speed. Also, the LE-20 is synchronized with the laser gun--and in most cases the gun does not detect that the reflection is not the original pulse. Instead, the gun just displays a targeting error code or a host of other obscure codes that the officer is likely to dismiss and simply move on to the next vehicle (the exception being the Stalker laser gun which sometimes displayed a code, no speed the remainder of the time).

The LE-20 operates for 5 seconds then shuts off. If the officer is persistent they will get get a speed reading but by then you will have already slowed down and your law abiding speed will displayed. Suspicion from the officer is reduced thanks to this behavior.

Sounds simple huh? Well, yes and no. For all this magic to work you must keep a few things in mind.

First and most important, the laser gun and the LE-20 must be able to see each other. Laser guns look at the world with an extreme sense of tunnel vision so if the transponder is not in it's field of view it won't even see the laser beam. Luckily, at the targeting distance an officer is likely to use the laser gun beam is a rectangle (not a cone, contrary to belief) about the size of the front of the vehicle so chances are good the gun and transponder will see and be seen by each other. With laser detection, distance is your friend as it yields a fairly wide view for the laser gun!

Alignment and placement of the LE-20 transponder is critical. The LE-20 must be aligned so it's beam is parallel to the ground (a level is provided for this task) and pointing straight ahead from the cars centerline. It's recommended that the LE-20 be placed near the front license plate. Officers are trained and conditioned to aim at the front license plate as it's the most reflective surface on the car (take a flash picture of a car at night and see what I mean), it's centrally located and easy to see at night. The handy thing about this is if you have a front plate the officer is probably going to continue to aim straight at the plate if he's having trouble getting a reading--it's his best target--all the while his gun is staring right in the face of a 17 watt laser. Having a front license plate on the front of your car is good insurance that the officer will target it. (front license plate haters crowd take note)

For larger vehicles such as SUVs, two transponders are recommended. Two transponders ensures that if the officer happens to target off center (perhaps aiming at a headlight) one of the LE-20 sensors is likely to see the laser gun.

Installation and Testing

Installation of the LE-20 involves mounting the transponder along with some simple wiring for powering the unit, the connections for the warning LED, warning speaker and a power switch. The LE-20 kit includes an assortment of brackets, perforated bars, required screws, double-sided tape, wiring connectors and a bubble level for aiming the laser.

This installation was done on an Allroad and I have previously done an install on my S4. The best location for the transponder on the Allroad was in the middle of one of the Audi rings in the grill--this required the removal of one horizontal slats with a dremel tool but resulted in a very clean, stealth installation.

Each installation will most likely be unique so this will just cover the basics. You'll need to put your thinking cap on to determine the best location for mounting the transponder. Lidatek provides good information and guidelines so it shouldn't be too difficult for other vehicles.

For the Allroad, use the supplied perforated bars and bend them into an upside down, squared off "J". Mount the long end of the "J" to the back of the bumper support with industrial double-sided tape (use solvent or alcohol to ensure surfaces are clean) and hook the small end of the "J" around the auxiliary cooling fan support and secure with a screw. Be sure to put protection (plywood or something) in front of the A/C condenser before drilling... you don't want your drill bit slipping and puncturing your $500 A/C condenser coil! Mount the transponder to the bar with the supplied mounting hardware.



Allroad Installation


S4 Installation

For the wiring, remove the lower knee panel to gain access under the dashboard. The panel is secured with five 8mm hex bolts. Two at the bottom of the dash panel on either side, one behind the fuse panel cover and two behind the trim piece at the top of the steering column (remove the cover by pulling the top towards you and slightly upwards). Gently lower the panel and disconnect the diagnostic cable and the footwell light wires, then remove the panel .

The cable for the transponder was routed across the fan support bracket, behind the headlight, along the side of the fender and through an available grommet in the firewall. The transponder cable plugs into a mating wiring harness for the inside wiring. The LE-20 requires a switched power source and ground. Lidatek supplies an easy to follow wiring diagram to get everything hooked up.


Wiring Diagram

The warning speaker is very loud --it's recommended that you simply mount it up under the dashboard somewhere with the supplied velcro. Even in our well insulated Allroad test vehicle the warning could easily be heard. We opted not to install the LED. I have the LED on my S4 but the audible warning is much more useful.

Testing

With the LE-20 installed it was time to head off and do some testing to see how it performed. Tests were performed with the Stalker Laser gun. The tests were not done under controlled scientific guidelines but rather the way an officer would be likely to use a laser gun.

The Allroad was equipped with a LE-20 and a Valentine One radar/laser detector to see if both devices were picking up on the laser gun. The vehicle was targeted at distances ranging from 500-1200 feet. Both the LE-20 and Valentine One detected each laser encounter.

When the vehicle was targeted without the LE-20 in operation the laser gun displayed the vehicle speed and distance almost instantly in all cases. Having used the gun, it's obvious why and unprotected driver has no chance against laser--very fast speed calculation.

With the LE-20 enabled, I was unable to get a speed reading during the 5 second period when the LE-20 was operating. The laser gun did display a distance reading but no speed and occasionally it displayed an E04 error code. At distances under 500 feet, I was occasionally able to get a speed reading depending where I aimed the laser gun. Bear in mind being targeted at ranges under 500 feet is probably not going to be a common occurrence as the officer is more likely to target vehicles at a distance--as mentioned earlier, distance is your friend.


Laser gun error code

Based on testing, the LE-20 does and excellent job giving the driver valuable time to check and adjust the vehicle speed if necessary. From my own real world experience, I've been spared a visit by the "man in blue" twice by the LE-20 installed in my S4 . On both occasions my speed was waaay outside the acceptable margin when I was first targeted--without the LE-20 I'm certain I would have been stopped both times. For effective laser protection the LE-20 works!

Contact Information:
Lidatek
12428 Hwy
99, Unit 51
Everett, WA
98204
http://www.lidatek.com/




Ok Dan. Please display proof that they don't work since in our last laser jammer thread you seemed to feel that these units aren't powerful enough and that I didn't provide "proof" that they work.

 

Hmmm, where to start again...

For one, I have to seriously question their CLAIMED 17W rating. To give you an example, laser pointers are generally regarded as a Class IIIa device, which means its output power is less than 5 milliWatts. Some extreme devices are considered Class IIIb, which means they output anywhere between 5-500 mW. Class IIIa devices are generally safe to look at for short periods of time without damage to the optic nerves, but you could temporarily see spots (look into a laser pointer for a few seconds to see what I mean). Class IIIb devices are a definite hazard to the optic nerves, even specular reflections of the beam (the reflection coming back from even non-shiny objects, such as a piece of paper).

To actually emit 17W, Lidatek would have to classify the laser as a Class IV device, and no governmental agency would EVER allow such a strong beam to be swung around in public. At that power, you would practically fry your optic nerves if someone just flashed it past your eyes. Anything greater in power than 2W per square centimeter is also an ignition hazard (i.e., it will burn your skin and set paper on fire)...at 17W, your skin would burn off as the beam passed over you. This doesn't even cover the extreme high voltage supplies needed to run such a beast, nor the heavy airborne contaminants that would be created by both the laser and supply (such as heavy concentrartions of ozone, a cancer causing agent).

SO, now that we know Lidatek is full of shit from the get go, do I really need to rehash what I've said in the past? I shouldn't need to, but I'll just remind everyone of a few useful points.

Now that we know the laser can NOT be anywhere NEAR 17 W, we have to assume it's no more powerful than a standard laser pointer (Class IIIa) if they want to legally manufacture and/or sell these things in the States. This brings us back to the original problem...the lasers/LEDs are NOT strong enough to provide BOTH a wide dispersion pattern AND a strong enough beam at the same time. So, what Lidatek does is focus the laser to a VERY tight beam pointing straight out from the car and HOPES that the officer is so far away as to make the angle between him and the car's centerline VERY tiny. If that condition doesn't hold true (which all too often I've seen that it doesn't), the system isn't pointing any useful energy towards the gun and therefore is all but useless. Well, OK, it might tell you that you're being hit since a light goes off, but the V1 does that for you anyhow. And again, even with the concentrated beam, the power is so low as to be practically useless in overpowering the reflection fro the actual gun.

I can't understand it, but you guys ALWAYS seem to fall into the same trap...it's printed in a magazine, or it's on the web, so it MUST be true. All it takes is a bit of forethought and some helpful knowledge from someone in the know and these things can easily be proven to work or not. That "review" was all but an ad for a product and reads like every other "ad/review" I've ever seen for similar products, ALL claiming to work. All I had to do was pick out a SINGLE "fact" from the article (and the "fact" was printed several times, so the chances of it being a misprint are smaller), and I could debunk the whole mess in one shot.

 

Macgyver
All i can say is the lidar system with my passport has saved me several times now. It must be doing something right.
I don't know how it works but I know mine have to be checked for level occasionally. I've had it 6 months.

fltsfshr

 

Dan, it seems that everyone wants to believe so badly that they will ignore evidence that runs contrary to what they want the truth to be. While I would be reluctant to trust my driving record to any device which is recommended by an article so desperately in need of an editor I do have a couple of questions. You refer to a 17 Watt laser as one which has a rated output of 17W/cm^2 while they may be referring to a laser device which CONSUMES 17W on the input side. How would that affect your argument? I agree that a laser, by its nature, will only affect that which it directly targets and most of the laser wielding police I have seen are on the side of the road, too far offline for this device to work as described. Given that, could YOU design a device that would work similarly to the one described except using multiple emitters to cover a wider area? Just a couple of random thoughts.

 

Another question, what is the power output of the laser the police use and why can't a jammer utilize an equal amount of power? Obviously, if it could then the signal from the jammer should be stronger than the reflected beam from the gun no?

 

Excellent....this is just what I wanted from you Dan.

Thanks!

( oh and one more thing. I know sometimes the internet can be funny with no emotion/body language/intonation. I've been on both sides of it before. I set this up as a challenge to get a really good reply from you. I am suspecting that Audiworld may be "in bed" with lidatek. I wanted more than just "it doesn't work" or "lidatek paid Audiworld to write that"

So thanks for stepping to the challenge and taking the time to reply! )

 

[QUOTE]Originally posted by Jenner
[B]Excellent....this is just what I wanted from you Dan.

Thanks!

( oh and one more thing. I know sometimes the internet can be funny with no emotion/body language/intonation. I've been on both sides of it before. I set this up as a challenge to get a really good reply from you. I am suspecting that Audiworld may be "in bed" with lidatek. I wanted more than just "it doesn't work" or "lidatek paid Audiworld to write that"

 

flt: I catch a LOT of flak from people about my bold statements on laser jammers, but they usually end up with statements like "Prove to me that they don't work!" I think the statement that SHOULD be made is "Prove to me that they DO work!" How do you know that the system is actually doing anything useful? Is it because you've successfully driven through an obvious speed trap without getting a ticket? Who's to say the officer was pointing the gun directly at YOUR car when you were warned? Maybe you got a signal, then managed to back off on the pedal enough before they actually got a reading.

When two scientists provided "proof" that cold fusion was possible, people wanted to believe in it so badly they blindly hailed them as miracle workers. It wasn't until months later when someone tried to reproduce those results that they realized the data was dubious, at best. The same holds true for laser jammers...people WANT to believe they work so badly that they will tout the wonders of it every time they breeze through a trap without a ticket, yet they have no way of checking the data for themselves, they only have the word of someone else (so to speak). I don't speed like a bat oput of hell, but I'm probably just up in the speeds where cops take notice. My V1 saves my ass not by providing me with an absolute signal, but by providing me a bit of warning so I can dip just below that speeding threshold that makes the cops take notice.

If a company tells me something is possible and they would like to sell me a product based upon that idea, I might be interested. But if multiple independant people, who have no interest in the product either way, come by and tell me the idea is actually quite impossible, I think I'm going to believe those unbiased people over the company trying to make money off of me.



laster: Try this link out for some more explanations...
https://www.s2ki.com/forums/showthread.php?...threadid=104501
...to give you the short and skinny, though, you mention exactly what I say in the thread above. With any emitter, you have a certain amount of energy to play with...you can either spray all of that energy into a tight cone, or you can spread it around in a huge swath. If you spread it around, there may not be enough energy at any one point to do any good. If you keep the cone tight to be powerful enough to do any good, you run the risk of it not pointing in the correct direction. Most LIDAR shots I've seen have been off to the side of the road with the officer hiding behind a bush or pylon, which means they usually hit you at a few hundred feet away, not half a mile away.

That being said, and as I mention in the thread above, I believe a jammer IS possible, and ChrisFromRI and I threw around a few ideas back then. The cost might be prohibitive for all but a few, but it IS possible.

On the laser power issue, 17W could be the input power, but to characterize the device as such would be silly...lasers are spec'd for a certain wavelength and a certain output power, not input power. Either way, even if it WAS input power, the output power would be significantly less as semiconductor laser diodes are quite inefficient (2-3%, usually), so that would put us back to the low power issue. On top of that, the pic they show is of a semiconductor laser diode (I know, not the one they use, but they all pretty much look the same)...my point is, though, the laser diodes are low wattage devices. At best you might see a 1W device for a VERY high price tag, so a 17W laser diode just isn't happening. Yet again, they screwed themselves over by showing the pic and emphasizing their lies.



Jenner: I try not to get out of hand, but when it comes to electronics and theory, I can be VERY passionate I'm always willing to concede a point if I'm proven wrong, but all too often people's idea of proof is "Because that's what I read...". If that were a useful way to prove theories, then according to the guy hanging out on the street downtown the world will end next week in a huge nuclear explosion and the cockroaches will rule the Earth I TRY not to make statements if I can't back them up with hardcore proof, and I can show you what kind of damage a 17W laser can do to skin. I also try not to take my discussions personally, but I DO take them seriously, mostly because I enjoy the work I do so much. Merri swears I should become a teacher

I can almost guarantee you Audiworld is in bed with Lidatek, along with several other companies. They both quote each other extensively. Audiworld is the online equivalent of Consumer Digest...Consumer Reports is fair because they receive their funding from the government, not advertising. Consumer Digest, on the other hand, receives its funding solely from advertisers, therefore they would be stupid to give a bad review...don't bite the hand that feeds you.

 

"On the laser power issue, 17W could be the input power, but to characterize the device as such would be silly...lasers are spec'd for a certain wavelength and a certain output power, not input power. Either way, even if it WAS input power, the output power would be significantly less as semiconductor laser diodes are quite inefficient (2-3%, usually), so that would put us back to the low power issue. "

Well, poorly vetted magazine articles may not make the distinction that engineers do re: input vs. output power. Also, if they can't spell, or use words correctly, (supposedly their own area of expertise) how can you expect them to be technically accurate or even keep track of their decimal points? Thanks, Dan, for helping to keep the level of bull down to a bearable level.

Larry

 

Thanks to all! These threads have been a wealth of information and the debate has been excellent. I have learned a lot from the threads, please keep updating the topic, many of us are glued to our PC's for the real results to magically appear.

My hat is off to all the contributers; good questions, good debate, and great information.