Lidatek LE-20 Laser Echo:
Evening the Odds
Article and Photos by: Don
Pavlik and Neil
McGarry
Neil and I 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 indium gallium arsenide laser (about 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.
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 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 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 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. 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. 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. 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!
Laser emitter
(not actual emitter, representative sample shown
for security reasons)
I installed an LE-20 on my S4 last year. My initial conversations about it:
My install ponderings
My
first experience with the LE-20
Contact
Information:
Lidatek
12428 Hwy
99, Unit 51
Everett, WA
98204
http://www.lidatek.com/
