Having just viewed an article on CNBC about the new LIDAR guns, it would
appear that a detector alone is useless. What is needed is a countermeasures
unit that locks on to the laser beam & jams it. Since we’re talking about
light here the FCC shouldn’t have much say in it. It should be real easy
for a detector to switch on a laser beam & direct it toward the gun to
‘blind’ it. Sounds like a good business oportunity here.
Also, since the LIDAR depends on finding a flat surface on the car, from which
to bounce the beam, cars with sloping hoods and little flat surface at the
front should be much harder to capture. It should be relatively easy to
eliminate flat surfaces. Matt black cars would also be more stealthy.
If that doesn’t work, you could hook up a couple of laser seeking missiles to
the LIDAR detector, so even if the cop did get you, he wouldn’t be around
to call it in! :) (Just joking, but it would look good in a movie!)
In <1992Aug18.000528.24…@encore.com> mpal…@encore.com (Mike Palmer) writes:
>Having just viewed an article on CNBC about the new LIDAR guns, it would
>appear that a detector alone is useless. What is needed is a countermeasures
>unit that locks on to the laser beam & jams it. Since we’re talking about
>light here the FCC shouldn’t have much say in it. It should be real easy
>for a detector to switch on a laser beam & direct it toward the gun to
>’blind’ it. Sounds like a good business oportunity here.
It would do some good they said it gives you about 1-second warning, and
that is assuming that when he first hits you with it that he is close enough
to get a lock on your car, hitting the brakes while he is trying to get a
lock will make if very difficult and he won’t know exactly how fast you
were going.
>Also, since the LIDAR depends on finding a flat surface on the car, from which
>to bounce the beam, cars with sloping hoods and little flat surface at the
>front should be much harder to capture. It should be relatively easy to
>eliminate flat surfaces. Matt black cars would also be more stealthy.
It is not the flat surfaces that get you, its the reflectors. They should
reflect far more of the laser beam than just about any flat surface on
the car. One of the magazines did a test and I seem to remember after
covering up the reflectors and the silver molding the range in which they
could lock on you was reduced enough to make the gun useless.
Roger Heflin
–
Roger…@Matt.ksu.ksu.edu Roger Heflin
>Also, since the LIDAR depends on finding a flat surface on the car, from which
>to bounce the beam, cars with sloping hoods and little flat surface at the
>front should be much harder to capture. It should be relatively easy to
>eliminate flat surfaces. Matt black cars would also be more stealthy.
I saw a short segment on the local news for LIDAR, and during that
segment, they were on a bridge, looking down at the *rear* of the
cars, targeting license plates at very short range.
So, you would need a jammer on the front and back.
Mike
—
mike%jim.u…@wupost.wustl.edu
mike%jim.u…@wupost.wustl.edu (Mike Suter) writes:
>I saw a short segment on the local news for LIDAR, and during that
>segment, they were on a bridge, looking down at the *rear* of the
>cars, targeting license plates at very short range.
Well, one good thing about that is the cosine error would really knock
the wind out of your apparent speed.
jim frost
j…@centerline.com
mpal…@encore.com (Mike Palmer) writes:
>Having just viewed an article on CNBC about the new LIDAR guns, it would
>appear that a detector alone is useless. What is needed is a countermeasures
>unit that locks on to the laser beam & jams it. Since we’re talking about
>light here the FCC shouldn’t have much say in it. It should be real easy
>for a detector to switch on a laser beam & direct it toward the gun to
>’blind’ it. Sounds like a good business oportunity here.
Mike is right. I just got a speeding ticket based on being clocked by a
LIDAR. The thing basically works like a military GLD (Ground Laser
Designator). If you get lased, it’s too late. The thing works great. The
cops let me try it out while they were filling out the ticket. It is
almost instantaneous (something like 1/30th of a second. If you happen to
have a LIDAR detector, and a car gets lased near you, there might be enough
reflected energy to set off a detector. The cops nailed me at 1600′ away.
>Also, since the LIDAR depends on finding a flat surface on the car, from which
>to bounce the beam, cars with sloping hoods and little flat surface at the
>front should be much harder to capture. It should be relatively easy to
>eliminate flat surfaces. Matt black cars would also be more stealthy.
Yeah, but if you are in a state that required front license plates, there
is a ready made flat surface.
Steve
—
Steve Bridges, Programmer/Analyst| NCR – Law Department, WHQ-5
st…@lawday.DaytonOH.NCR.COM ___| Phone:(513)-445-4486 622-4486 (VOICEplus)
Reserve sci.military moderator| "The airplane does not recognize attitude,
providing a maneuver is conducted at one G" — A.M. "Tex" Johnston
In article <jimf.714166…@centerline.com> j…@centerline.com (Jim Frost) writes:
>Well, one good thing about that is the cosine error would really knock
>the wind out of your apparent speed.
can’t they correct for the cosine error?
i know the angle changes as the car goes by, but if you clock it
when it’s at a certain spot on the road, the change should be fairly small.
-teddy
p.s. not that i *want* them to, you understand…
>>I saw a short segment on the local news for LIDAR, and during that
>>segment, they were on a bridge, looking down at the *rear* of the
>>cars, targeting license plates at very short range.
>Well, one good thing about that is the cosine error would really knock
>the wind out of your apparent speed.
True, but this would decrease as they increased their target range.
Mike
—
mike%jim.u…@wupost.wustl.edu
QUIT
post.wustl.edu
>It is not the flat surfaces that get you, its the reflectors. They should
>reflect far more of the laser beam than just about any flat surface on
>the car. One of the magazines did a test and I seem to remember after
>covering up the reflectors and the silver molding the range in which they
>could lock on you was reduced enough to make the gun useless.
> Roger Heflin
>–
>Roger…@Matt.ksu.ksu.edu Roger Heflin
What about putting a tinted cover over the reflectors (i.e. dark tinted
headlight covers)? Would this help?
Lee Reese
l…@gwinnett.com
In article <1992Aug24.212714.2327%jim.u…@wupost.wustl.edu> mike%jim.u…@wupost.wustl.edu (Mike Suter) writes:
>I have seen many cars around here (Missouri) lately with various
,
>plastic license plate covers. If these are legal (or even if not
>one could probably make a cover that would scatter the laser emission,
>which may give the driver enough time to detect the transmission and
>check his speed. (the demonstration of the LIDAR devices I saw had
>the operators aiming the guns at the (rear) license plates)
>What do you all think?
i think that this is silly and unnecessary.
CMI (the people who brought you the Escort and Passport) have done
some studies, and concluded that simple atmospheric scatter is
sufficient to meet anyone’s needs for laser detection. their
$100 laser detector is good for 2 to 3 miles of warning, subject to
the usual cautions about instant on type devices being used by revenue
enhancement officials, and the resulting need to be very careful traveling
on empty highways.
cheers,
richard
—
richard welty 518-393-7228
we…@cabot.balltown.cma.com
“if you can read this, mario, you’re too close”
— bumper sticker seen on a CART safety truck
> What you’d have to do is get a cover made of a material which is
>strongly absorbing in the IR frequency range, but still clear enough
>in the visible so that your plate is still readable. This cover would
>be be tipped upwards to prevent specular reflections returning to the
>lidar set. A (dull) IR-absorbing coating on the plate would have the
>same effect.
Ok–now where is this stuff sold?
> Unfortunately, you have the same problem with your rear
>reflectors.
Yeah, but if you sprayed this stuff on all your reflectors and
lense covers……
Mike
—
mike%jim.u…@wupost.wustl.edu
i…@lcs.mit.edu (Lee Hetherington) writes:
>I wonder if such simple IR-absorbing coatings are readily available.
>If they were, wouldn’t the military spray/coat all their vehicles with
>them to make them invisible to IR night-vision systems? I haven’t
>heard of such a thing.
It’s quite different to absorb an externally applied IR beam in the
milliwatt range than to stop a vehicle’s engine from radiating in the
IR range.
The former can be done with a thin film such as a paint (it is, after
all, what most pigments do for light in the visible range). The
latter takes insulation — and there’s just so long you can contain
the heat of an engine before something inside the insulation is pretty
damned hot.
jim frost
j…@centerline.com