Laser 'marksman' should join Bin Laden hunt
Get him on Our Side
Letters As reported yesterday, there is a man in New Jersey being publicly flogged for allegedly beaming a green laser into the eyes of two jet pilots. The fellow - David Banach - claims to have been pointing out stars to his young daughter and to have accidentally hit the plane with his beam. The Feds, however, have lobbed very serious threats at Banach, charging him under a provision of the Patriot Act for disrupting the operators of a mass transportation vehicle.
Depending on your view point, Banach may have made a simple mistake or may have been very irresponsible. Or he may have been part of one of the most miraculous feats of all time.
Is it really possible to shoot a laser pointer into a pilot's eyes from a few thousand feet away? Our readers tackle this tough question and come up with few answers.
At 1 km a good semiconductor laser will produce a spot 8m+ in diameter (assuming 0.5 degrees beam divergence). There is no way in hell anyone can be blinded by this. In fact if you look at it from the beam side from 1km+ it will look like someone is blinking with a very weak lamp.
The only way for it to be detected and identified as laser would have been if the plane carried a missile launch warning system. These detect and warn about laser illumination at a number of "popular" wavelengths, because it is used in modern shoulder launched systems to determine distance to target and target speed prior to launch.
Which brings the more interesting question - who is the paranoid twat that has put such a system on his business jet and what is the reason for him to be paranoid.
Rather than prosecuting him, shouldn't they be recruiting him to run the Star Wars defence program? A 1 in 3 hit rate success on a 1 cm diameter target flying through the air must be beyond the wildest dreams of the NSA boffins.
We had a similar thought, Nick. Even if old Bin Laden was flying through the air at 180 mph and was 5,000 feet away, Banach should be able to nail him square between the eyes. This is the kind of marksman we need on our side.
While the odds of shining a laser in a pilot's eye from the ground are quite slim, It's said that the actual problem is that the windshield of the cockpit tends to scatter the beam, making the experience really annoying for the pilot. I believe this brief but intense annoyance is what is being referred to as "temporary blindness".
I hardly think there is any particular danger to pilots, especially as much stronger visible and invisible lasers are already used at some airports as landing guidance systems.
Instead of the Patriot Act being applied here, we need a Dumbass Act, where if you are found to have committed a moronic, jackass stunt that caused a great deal of inconvenience and hassle for people who have better things to worry about, they put you in stocks on the busiest street corner of your home town, just for a few days, so that all your old school chums can come by and tell you what a jerk you are, throw food at you, and give you a good solid kick in the rump.
The feds' story is bunk. OK, I admit it, I have a green laser. I ALSO have green laser fiber optic testers (as part of my job).
My green laser (a class III laser -- 5 mW) is _incredibly_ more powerful than my fiber optic testers (class I lasers -- 1 mW).
Furthermore, I've actually done distance tests with my green laser, successfully hitting objects that were 3/4ths of a mile away. That's _just_ shy of 4000 feet. But it was almost _impossible_ to do; the object in question was a _large_ church and most importantly, NOT MOVING.
Even so, in order to get a class III to shine that distance, I had to hold onto the laser with both hands AND "trace" the laser along other objects along the way, so that I could maintain a true direction towards the church. Aiming the laser "cold" at the church was impossible; the laser was always off by a micron or two on my end and would miss the church entirely.
The point is, though, that short of mounting a laser on a tripod, it's just not possible for this guy to hit a moving airplane, much less three times. When you factor in the laser's probable power it's even _more_ unlikely.
The only way I can even attempt to get the feds' story to "work" is if the guy lived _extremely_ close to the airport, and was also in the planes flight path, and had the planes fly into the laser rather than targeting them. But that's a lot of ifs that have to go exactly right before anything happens.
(And yeah, back when I got my class III, I tried hitting a bunch of airplanes. Don't tell the feds. I never got anywhere even close! :) )
All lasers have a divergence associated with them (for fine lasers this can be in the microradians to miliradians) and as such the beam size increases with distance. That would surely aid in hitting the pilot.
People are shining lasers at airplanes to blind the pilots to bring the planes down...From 15 miles away...not 2...not even a 1000 yards...15 miles...Not only would the beams probably not make it, even if they do they would be so diffused as to be almost unseeable...
but that isn't the best part...in order to 'attack' a plane with laser pointers you would have to put your pointer on the dime sized portion of an open eye moving at a minimum of 140 miles per hour on approach....for a minute and a half...from SEVERAL miles away...with a $2.99 hand held laser pointer powered by a AAA battery...I'm not an MIT graduate but I'm going to go out on a limb and say that's not really feasible...Not even if you mount it on a platform like binoculars or a rifle or a tripod....it's just not going to happen...
If it could, I would hope the uber bazillion dollar missile defense program was a little more successful...
I don't normally wear a tin foil hat but it seems that quite a few people in the world should if any of them are buying this story...
dennis de st jeor
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