Yes, my entire taillight assemblies were ripped off in a mall parking lot
from my 86.5 Nissan Hardbody Pickup.
It was so easy for them it was pitiful but I just never noticed it before.
They are held on by two little bolts from the inside of the bed and then
they unplug conveniently from the wiring harness for instant removal.
On my new ones I have the phillips/bolt head ground and drilled
out and lock-tite’d into position. Now I only have to fear a bulb
failure since I can’t get at them anymore either without cutting the bolts.
(I also added a locking gas cap, a kill switch and more lock-tite and
fat washers on the tailgate supports to slow the removal of the tailgate,
all for therapeutic reasons – Damn, I hate getting ripped off)
Oh, and the reason for this post, primarily, is that the dealer where I
bought the replacements said they are selling a LOT of them lately, so BEWARE
all you Nissan Hardbody Pickup Owners out there.
—
\ _
0 0 Tim Mortensen
(
\__ t…@manta.dwp.la.ca.us
Driving along SC Highway 93 near jolly olde Clemson University one night
last week I saw something rather curious. The car behind me, a newish
Nissan 300ZX, had a strange device implanted in the nose. It appeared
to be a bar about a foot long and maybe two inches high, in which a dim
red light went from side to side. The light took about three seconds to
make a round trip, and was just a wee bit brighter near the center of the
bar. The only thing I’ve ever seen like it was the "sensor array" in the
nose of the "KITT" Firebird on the TV show "Knight Rider" several years
ago, and at first I thought maybe some dork had made one of those trying
to be cool back when the show was on the air, but that thought went south
when I identified the car as a new-style black 300ZX Twin Turbo. Then I
got to thinking "Hmmm, dim red sweeping light, probably invisible in day-
light, relatively inconspicuous fast car, fairly bemonied owner, in a town
with a university known for its engineering school, could it perhaps be a
lidar jammer/scrambler/disruptor device?" If anyone has seen this car, or
any with a device similar to this, do you know what it is? Meanwhile, I’m
scrutinizing the nose of every black Turbo Z that I see, just looking…
Shane Roach
csro…@eng.clemson.edu
- Hide quoted text — Show quoted text -
In article <1992Sep29.210326.25…@hubcap.clemson.edu> csro…@eng.clemson.edu (Shane Roach) writes:
>Driving along SC Highway 93 near jolly olde Clemson University one night
>last week I saw something rather curious. The car behind me, a newish
>Nissan 300ZX, had a strange device implanted in the nose. It appeared
>to be a bar about a foot long and maybe two inches high, in which a dim
>red light went from side to side. The light took about three seconds to
>make a round trip, and was just a wee bit brighter near the center of the
>bar. The only thing I’ve ever seen like it was the "sensor array" in the
>nose of the "KITT" Firebird on the TV show "Knight Rider" several years
>ago, and at first I thought maybe some dork had made one of those trying
>to be cool back when the show was on the air, but that thought went south
>when I identified the car as a new-style black 300ZX Twin Turbo. Then I
>got to thinking "Hmmm, dim red sweeping light, probably invisible in day-
>light, relatively inconspicuous fast car, fairly bemonied owner, in a town
>with a university known for its engineering school, could it perhaps be a
>lidar jammer/scrambler/disruptor device?"
More likely, it’s some dork who regularly watches reruns of Knight Rider
in syndication somewhere and thought it would be cool to have a "Cylon
Eye" (remember Battlestar Galactica?) on the nose of his car.
LIDAR works in the infrared band. This device needs to emit lots of IR,
NOT visible light, in order to drown out reflections from LIDAR guns.
Beyond that, why would it need to "scan" from side to side? Moving back
and forth like that reduces the device’s effectiveness: the device might
be "looking" to the left when the LIDAR beam comes in from the right,
making it totally useless. It would be better to have the emitter run the
full width at all times, like a fluorescent light tube, therefore covering
the entire front of the vehicle at all times. There would also probably
be another one across the rear, perhaps hidden in the full-width
spoiler. Above all, such a device would best be made stealthy, so that
Officer Friendly won’t pull you over and say "What’s that thing? Looks
illegal – I’m going to have to haul you downtown and have it impounded."
I think it’s fairly safe to say that this device was NOT a LIDAR jammer,
or, if it is, it’s a very poorly designed one.
Counterarguments?
[description of z-car with "kitt" light deleted]
What you saw was just a cute little accessory. JC Whitney sells
(or used to sell) them. I almost got one for my old Skylark. 8^)
They’re probably illegal, too.
Cheers
—
j…@access.digex.com | (Cage) 1991 323se ZCP-710 | Comus Road
Merry Land (MD) U.S.A. | (Bike) 1986 GSXR750 (sold) | ClarksBURG
——————————————————————————
NeXTstep 3.0: Have you hugged *your* object today?
With all this talk of laser jamming, I was wondering whether or not this
is in fact a viable option. Simply put, is it possible to emit a
harmless (to other motorists and passersby) infra-red light source
that would cause LIDAR detectors to fail?
This must be addressed on a number of levels:
1. Electro-optics
2. The structure of the gun.
3. An unfocused wide-spread emission.
Any takers?
From article <BvE9MG….@news.cso.uiuc.edu>, by t…@uiuc.edu (Khan):
> LIDAR works in the infrared band. This device needs to emit lots of IR,
> NOT visible light, in order to drown out reflections from LIDAR guns.
I know that LIDAR operates in IR, but it seems as if something emitting a
substantial quantity of IR might also emit a little bit of visible, but
very dim, red light. This might be especially so if it was an experimental
design, just working on the concept before polishing the product.
> Beyond that, why would it need to "scan" from side to side? Moving back
> and forth like that reduces the device’s effectiveness: the device might
> be "looking" to the left when the LIDAR beam comes in from the right,
> making it totally useless. It would be better to have the emitter run the
> full width at all times, like a fluorescent light tube, therefore covering
> the entire front of the vehicle at all times. There would also probably
> be another one across the rear, perhaps hidden in the full-width
> spoiler. Above all, such a device would best be made stealthy, so that
> Officer Friendly won’t pull you over and say "What’s that thing? Looks
> illegal – I’m going to have to haul you downtown and have it impounded."
Why would it scan? I dunno. But the fact that this device was mounted on
a black car might give the driver enought of an advantage(in longer lock-on
times) that he could use a slower scan at this stage of development. It
probably would be better in terms of constant coverage to have the emitter
on full-width all the time, but this setup may yield a wider angle of cover-
age and use less power. Also, I don’t think it’d be difficult, with a little
work, to make the device stealthy. This one seemed to be in the strip between
the combination lights, just above the upper air intake. As for putting one
on the rear of the car, it would best be concealed on a new-style Z by placing
it between the taillights. There’s a handy black panel there, installed at
the factory.
> I think it’s fairly safe to say that this device was NOT a LIDAR jammer,
> or, if it is, it’s a very poorly designed one.
Maybe it is, maybe it ain’t. I don’t know. But in the event that it is, I
thought it would be nice to spread the word.
csro…@eng.clemson.edu (Shane Roach) writes:
>Why would it scan? I dunno. But the fact that this device was mounted on
>a black car might give the driver enought of an advantage(in longer lock-on
>times) that he could use a slower scan at this stage of development. It
>probably would be better in terms of constant coverage to have the emitter
>on full-width all the time, but this setup may yield a wider angle of cover-
>age and use less power.
WHY do you guys drop into these deep discussions based on NO understanding
of the topic?
Here are a few facts. First off, there is a company
that advertises in "Kit Car" magazine that makes all the stuff necessary
to make your car look like "Kit" from that TV show. That includes the
LED scanner. Someone’s idea of customizing, I guess. Second, a scanning
jammer such as you described simply would not work. Anyone who knows
enough about electronics to build a true jammer would presumably
have done a bit of homework to learn how the LIDAR works. One
important aspect is under ideal (worst for us) conditions, the Laser
Atlanta/Kustom Signals LIDAR can acquire a reading in a few milliseconds.
In practice it seldom works that way but one does not design jammers
for typical cases. Third, no IR laser – what is needed to jam these
things – emits ANY visible light.
I’ll bet if you’d looked you’d have seen an LED license tag frame, one
of those that rotates, on that same car.
John
—
John De Armond, WD4OQC |Interested in high performance mobility?
Performance Engineering Magazine (TM) |
Marietta, Ga |Interested in high tech and computers?
j…@dixie.com |Write me about PE Magazine
Need Usenet public Access in Atlanta? Write Me for info on Dixie.com.
In article <1actbmINN…@early-bird.think.com> sh…@Think.COM (Shai Guday) writes:
>With all this talk of laser jamming, I was wondering whether or not this
>is in fact a viable option. Simply put, is it possible to emit a
>harmless (to other motorists and passersby) infra-red light source
>that would cause LIDAR detectors to fail?
If it could be produced, it would definitely be a hot commodity. Pun
intended.
In article <1actbmINN…@early-bird.think.com> sh…@Think.COM (Shai Guday) writes:
>With all this talk of laser jamming, I was wondering whether or not this
>is in fact a viable option. Simply put, is it possible to emit a
>harmless (to other motorists and passersby) infra-red light source
>that would cause LIDAR detectors to fail?
x
The concept is simple: direct a IR beam at the LIDAR detector which
is of sufficient amplitude to swamp the "desired" signal, and which
is of appropriate frequency (measured at the receiver, so don’t forget
your vehicle’s motion) to read either <speed limit or a random
failure.
The bigger problem is in aiming your jammer at the LIDAR and doing so
fast enough to avoid all true readings. A continous, wide-angle
beam will dothis.
The remaining physics is relatively straightforward and doesn’t differ
much from the radar equation used to build a radar jammer.
The philosophical/moral question is not so straightforward and is not
appropriate to this group anyway.
–
Carl Witthoft @ Adaptive Optics Associates
aoa!c…@bbn.com c…@aoa.utc.com
54 CambridgePark Drive, Cambridge,MA 02140 617-864-0201
"My Karma just ran over my Dogma!"
c…@aoa.aoa.utc.com (Carl Witthoft) writes:
>x
>The concept is simple: direct a IR beam at the LIDAR detector which
>is of sufficient amplitude to swamp the "desired" signal, and which
>is of appropriate frequency (measured at the receiver, so don’t forget
>your vehicle’s motion) to read either <speed limit or a random
>failure.
>The bigger problem is in aiming your jammer at the LIDAR and doing so
>fast enough to avoid all true readings. A continous, wide-angle
>beam will dothis.
>The remaining physics is relatively straightforward and doesn’t differ
>much from the radar equation used to build a radar jammer.
Actually the physics are fundimentally different. The LIDAR (the Laser
Atlanta unit at least) works by making a sequence of timed distance
measurements and computes speed from delta distance/delta time. It does
NOT use doppler in any manner.
I would imagine it would take a fairly powerful and pretty close to
(optical) frequency to jam the unit. Doable but not trivial. I’ll
know more in a couple of months when I get one in for evaluation.
John
–
John De Armond, WD4OQC |Interested in high performance mobility?
Performance Engineering Magazine (TM) |
Marietta, Ga |Interested in high tech and computers?
j…@dixie.com |Write me about PE Magazine
Need Usenet public Access in Atlanta? Write Me for info on Dixie.com.
In article <b=fp…@dixie.com> j…@dixie.com (John De Armond) writes:
>I would imagine it would take a fairly powerful and pretty close to
>(optical) frequency to jam the [lidar] unit. Doable but not trivial.
>I’ll know more in a couple of months when I get one in for evaluation.
>John De Armond, WD4OQC
>Marietta, Ga
I’m the person who originally suggested jamming lidar with
military surplus IR spotlights. The basic argument is that
(1) The laser is in the milliwatt range. It can’t get higher, for
reasons of size, weight, power supply, and last but not least, safety.
(2) The receiver has to pick up the laser pulses in the microwatt
range – only a fraction of the light will be reflected back to the
gun. A receiver sensitive to such low levels probably (note
qualification) has a limited upper range, and can be swamped.
(3) The receiver is probably as inexpensive as possible, and relies
more on time domain intensity variations to identify it’s returned
signal than on precise frequency discrimination.
(4) Therefore a jamming device does not need to be exactly the same
frequency as the laser source – it just needs to return enough energy
in the entire frequency range in which the detector is sensitive to
overwhelm it. (Note that this can be countered with a frequency
specific filter on the detector).
John, when you get your hands on a lidar gun, a lot of us will be
interested in what you find. For a start:
* What warnings vs, say, pointing it at the sun, does it carry?
* What happens when you point it at a very HOT car – say a black paint
job that’s been sitting in the Georgia sun all day?
* If we can’t do a brute force intensity jam, how about an intense,
rapidly flickering IR source (eg, hot object behind fan blades)?
* How well does a license plate cover reduce IR return? Glass?
Plastic? Should we rely on absorption or reflection away from
the lidar? What can we do about rear (and front) reflectors?
Peter Trei
pt…@mitre.org
N1MNV
I’m interested in knowing if the laser doesn’t work on different types of
paint jobs.
If laser works on reflecting light…. then if I have a "buff" black car
that absorbs most light…would I be stealth.
Another thought re: laser detectors. Are they only working on deflection
from atmosphere particles? Or does it work on the laser hitting the car
itself. The latter would be too late, wouldn’t it?
—
Teek (Prateek Dwivedi) t…@kingcong.uwaterloo.ca
Research Assistant pdwiv…@systems.watstar.uwaterloo.ca
Flight Control Systems Group (519)885-1211 x5314 Voice
University of Waterloo, Canada (519)746-3077 Fax
In article <Bvps0r….@watserv1.uwaterloo.ca> t…@kingcong.UWaterloo.ca (Prateek Dwivedi) writes:
}If laser works on reflecting light…. then if I have a "buff" black car
}that absorbs most light…would I be stealth.
No. They’ll aim for your headlights, bumper, license plate…
}Another thought re: laser detectors. Are they only working on deflection
}from atmosphere particles? Or does it work on the laser hitting the car
}itself. The latter would be too late, wouldn’t it?
Yes, it would be too late. The hope is that the cop guns somebody in
front of you, and you pick up some of that signal as it’s bouncing around.
Jeff
—
Jeffrey S. Curtis sidewin…@uiuc.edu | "Resplendent and full again, they revel
The Power of 37 free2207 at uiucvmd | in their role as self-appointed critics
"To be great is to be misunderstood." | of the establishment…"
"Insist on yourself – never imitate." | — INXS _Welcome to Wherever You Are_
pt…@bistromath.mitre.org (Peter Trei) writes:
:
: (3) The receiver is probably as inexpensive as possible, and relies
: more on time domain intensity variations to identify it’s returned
: signal than on precise frequency discrimination.
I would presume that the lidar broadcaster sends out sequence pulses with
very particular shapes, and uses some sort of lock-in receiver or matched
filter to search for only that particular pulse shape, and ignore
all others. That may make it hard to jam.
: Peter Trei
: pt…@mitre.org
: N1MNV
:
–
-Matt Kennel m…@inls1.ucsd.edu
-Institute for Nonlinear Science, University of California, San Diego
-*** AD: Archive for nonlinear dynamics papers & programs: FTP to
-*** lyapunov.ucsd.edu, username "anonymous".
In article <b=fp…@dixie.com> j…@dixie.com (John De Armond) writes:
- Hide quoted text — Show quoted text -
>c…@aoa.aoa.utc.com (Carl Witthoft) writes:
>>x
>>The concept is simple: direct a IR beam at the LIDAR detector which
>>is of sufficient amplitude to swamp the "desired" signal, and which
>>is of appropriate frequency (measured at the receiver, so don’t forget
>>your vehicle’s motion) to read either <speed limit or a random
>>failure.
>>The bigger problem is in aiming your jammer at the LIDAR and doing so
>>fast enough to avoid all true readings. A continous, wide-angle
>>beam will dothis.
>>The remaining physics is relatively straightforward and doesn’t differ
>>much from the radar equation used to build a radar jammer.
>Actually the physics are fundimentally different. The LIDAR (the Laser
>Atlanta unit at least) works by making a sequence of timed distance
>measurements and computes speed from delta distance/delta time. It does
>NOT use doppler in any manner.
>I would imagine it would take a fairly powerful and pretty close to
>(optical) frequency to jam the unit. Doable but not trivial. I’ll
>know more in a couple of months when I get one in for evaluation.
>John
>–
>John De Armond, WD4OQC |Interested in high performance mobility?
>Performance Engineering Magazine (TM) |
>Marietta, Ga |Interested in high tech and computers?
>j…@dixie.com |Write me about PE Magazine
>Need Usenet public Access in Atlanta? Write Me for info on Dixie.com.
Ever since I heard about the laser speed-measuring unit, I have wondered how
it worked. As described on our local evening news, the police shine a
single laser beam onto the car, and it reflects back to the unit [?]
How is that? Surely most/all surfaces of the car are not angled such
as to give reflection straight back to the unit, and I would imagine
that the laser is a fairly narrow beam. So, how does it work?
Just curious …
[my Plymouth Horizon can scarcely go fast enough to speed,
so I have no need to jam the gizmo]
John
sny…@henry.ece.cmu.edu
pt…@bistromath.mitre.org (Peter Trei) writes:
>(1) The laser is in the milliwatt range. It can’t get higher, for
>reasons of size, weight, power supply, and last but not least, safety.
>(2) The receiver has to pick up the laser pulses in the microwatt
>range – only a fraction of the light will be reflected back to the
>gun. A receiver sensitive to such low levels probably (note
>qualification) has a limited upper range, and can be swamped.
>(3) The receiver is probably as inexpensive as possible, and relies
>more on time domain intensity variations to identify it’s returned
>signal than on precise frequency discrimination.
The laser is low power but as best I can tell, the unit uses interferometry
which provides a high degree of discrimination to other sources of light.
Plus the gun has what looks like a dichroic bandpass filter on the
receiver. More selectivity.
Note that at a retail price of more than $5000, the technology does not
have to be cheap and does not seem to be.
>(4) Therefore a jamming device does not need to be exactly the same
>frequency as the laser source – it just needs to return enough energy
>in the entire frequency range in which the detector is sensitive to
>overwhelm it. (Note that this can be countered with a frequency
>specific filter on the detector).
You need to realize what you’re saying. The range of frequencies of light
that falls within the nominal range of IR is massive, comprising many
octaves. A radio analogy would be to attempt to jam a highly selective
VHF receiver using a wideband noise source that covers from AM broadcast
to microwave. Even with massive total power from the jammer, the power
concentrated in the band of interest is minimal. You simply will have
to know more about the IR used in order to jam. Once you DO know something
about it, generating the necessary power is easy.
> John, when you get your hands on a lidar gun, a lot of us will be
>interested in what you find. For a start:
I have already had my hands on one for a few minutes. Because of the
source, no more details regarding the incident are available.
>* What warnings vs, say, pointing it at the sun, does it carry?
No markings on the gun.
>* What happens when you point it at a very HOT car – say a black paint
> job that’s been sitting in the Georgia sun all day?
Probably nothing, as noted above.
>* If we can’t do a brute force intensity jam, how about an intense,
> rapidly flickering IR source (eg, hot object behind fan blades)?
My guess is an array of laser diodes shining through a suitable diffuser
would be the most effective jammer. Given the low price of laser diodes
these days, this would be very inexpensive to construct.
>* How well does a license plate cover reduce IR return? Glass?
> Plastic? Should we rely on absorption or reflection away from
> the lidar? What can we do about rear (and front) reflectors?
This is light. You can easily test your hypothesis by simply shining a
light on your car and observing the reflection. The LIDAR is not as
sensitive as your eyes so filter your view appropriately.
I spent my time with the gun doing what cops would do – shooting at cars.
My experience was quite similar to _Car & Driver_ in that it is a difficult
unit to operate and requires steady aim. I only had about 5 minutes with
it so I have only first impressions. I believe a good defence will be to
minimize the reflective surfaces on the car and to use a detector. Though
the gun can acquire a reading in under a second under ideal conditions,
under real world conditions it will require several seconds. I’d not
be surprised to hear someone has developed a clearcoat with IR absorbance
properties. The market is certainly pregnant.
John
—
John De Armond, WD4OQC |Interested in high performance mobility?
Performance Engineering Magazine (TM) |
Marietta, Ga |Interested in high tech and computers?
j…@dixie.com |Write me about PE Magazine
Need Usenet public Access in Atlanta? Write Me for info on Dixie.com.
In article <1992Oct7.001945.17…@fs7.ece.cmu.edu>,
sny…@henry.ece.cmu.edu (John Snyder) writes…
>Ever since I heard about the laser speed-measuring unit, I have wondered how
>it worked. As described on our local evening news, the police shine a
>single laser beam onto the car, and it reflects back to the unit [?]
>How is that? Surely most/all surfaces of the car are not angled such
>as to give reflection straight back to the unit, and I would imagine
>that the laser is a fairly narrow beam. So, how does it work?
From what I’ve read, the unit sends out a sequence of pulses and times
each individual return. However, because the spread in responses would be very
large compared to the accuracy required to deduce the speed from two readings
(e.g. compare the return time difference between one pulse that hits the
cage^H^H^H^Hcar’s headlights and one that reflects from the windshield, with
the accuracy needed to determine a vehicle’s speed to 1 mph in 60 for two
pulses say 1/50 sec apart), the timed returns have to fit to a straight line
within a certain accuracy over a certain period before the unit declares a
valid velocity reading. Given this, I’m sure you can think of several passive
and active ways to bamboozle the unit — it’s not instantaneous. A valid
return would be at very low intensity since, as you noted, a true specular
reflection is very unlikely, so car-mounted jammers have a good chance of
over-riding returns (though you can also think of ways the lidar manufacturer
can minimise this…).
>Just curious …
>[my Plymouth Horizon can scarcely go fast enough to speed,
>so I have no need to jam the gizmo]
>John
>sny…@henry.ece.cmu.edu
Ivan Reid, Paul Scherrer Institute, CH. i…@cvax.psi.ch
GSX600F, RG250WD. SI=2.66 "You Porsche. Me pass!" DoD #484
In article <Bvps0r….@watserv1.uwaterloo.ca> t…@kingcong.UWaterloo.ca (Prateek Dwivedi) writes:
>I’m interested in knowing if the laser doesn’t work on different types of
>paint jobs.
>If laser works on reflecting light…. then if I have a "buff" black car
>that absorbs most light…would I be stealth.
Only if all your chrome, your headlights, your license plates, your
reflectors (e.g. turn signals, fog lights, etc.) are ALL painted dull
black as well. If your car if flat balck, but you have a nice shiny
license plate, a LIDAR gun will still be able to get a reading from your
car.
>Another thought re: laser detectors. Are they only working on deflection
>from atmosphere particles? Or does it work on the laser hitting the car
>itself. The latter would be too late, wouldn’t it?
You’re absolutely right. There is no "scatter" from a LIDAR gun, and its
beam is very narrow. When your LIDAR detector goes off, it’s because the
LIDAR beam is hitting YOUR CAR. It doesn’t bounce off of other vehicles,
trees, the road, signposts, or any of the other things that RADAR will.
This is why Car & Driver judged LIDAR detectors to be worthless in their
report on LIDAR.
In article <1992Oct7.001945.17…@fs7.ece.cmu.edu> sny…@henry.ece.cmu.edu (John Snyder) writes:
>Ever since I heard about the laser speed-measuring unit, I have wondered how
>it worked. As described on our local evening news, the police shine a
>single laser beam onto the car, and it reflects back to the unit [?]
>How is that? Surely most/all surfaces of the car are not angled such
>as to give reflection straight back to the unit, and I would imagine
>that the laser is a fairly narrow beam. So, how does it work?
Probably the same way any spotlight works. Remember the car is not
a perfect mirror, some light is scattered in all directions. This
misunderstanding is probably the result of the sloppy way we use
words in normal conversation (and the news media). In scientific
terms the laser beam is scattered and part of it returns to the
unit.
In article <Bvpxo9….@news.cso.uiuc.edu> jsc52…@uxa.cso.uiuc.edu (Jeffrey S. Curtis) writes:
>}Another thought re: laser detectors. Are they only working on deflection
>}from atmosphere particles? Or does it work on the laser hitting the car
>}itself. The latter would be too late, wouldn’t it?
>Yes, it would be too late. The hope is that the cop guns somebody in
>front of you, and you pick up some of that signal as it’s bouncing around.
I was in Wal-Mart yesterday and noticed they had a BEL Laser Detector
for around $100. It claimed up to a 5 mile range.
Is this one of them that was recently tested in a car magazine
article?
Has anyone actually tried one yet?
Russ (rlat…@decster.uta.edu)
In article <Bvpxo9….@news.cso.uiuc.edu> jsc52…@uxa.cso.uiuc.edu (Jeffrey S. Curtis) writes:
>In article <Bvps0r….@watserv1.uwaterloo.ca> t…@kingcong.UWaterloo.ca (Prateek Dwivedi) writes:
>}Another thought re: laser detectors. Are they only working on deflection
>}from atmosphere particles? Or does it work on the laser hitting the car
>}itself. The latter would be too late, wouldn’t it?
>Yes, it would be too late. The hope is that the cop guns somebody in
>front of you, and you pick up some of that signal as it’s bouncing around.
Suppose for a bit of cleverness, the lidar designers use a pulsed
laser and detect synchronously with the pulses. If they used a
pseudorandom time-sequence of pulses, the jammer-designer would have
to overpower the high peak power of the pulsed laser and match the
time-sequence of the pulses to within nanoseconds. Would you really
want to spend on the order of $50K for a jammer to avoid paying of
order $1K in tickets?????
—Jon
—
Disclaimer — The government probably disagrees with my opinions.
gilli…@bldrdoc.gov (Jonathan M. Gilligan) writes:
>Suppose for a bit of cleverness, the lidar designers use a pulsed
>laser and detect synchronously with the pulses. If they used a
>pseudorandom time-sequence of pulses, the jammer-designer would have
>to overpower the high peak power of the pulsed laser and match the
>time-sequence of the pulses to within nanoseconds. Would you really
>want to spend on the order of $50K for a jammer to avoid paying of
>order $1K in tickets?????
I don’t think so Jon – watching some police work with the units – it is
very easy to get an error READING mainly due to an error in it’s
checking algorithm. - I belive that all you have to do is to put out
noise on the same frequency and it’s error checking will sut it down!