Posted on 09/28/2004 8:12:49 PM PDT by ableChair
Greta Van Susteren reported that a Delta pilot enroute to Salt Lake City was lazed in the cockpit this last Wednesday. Only country I know that has that hardware (for lazing bomber pilots) was the Soviet Union. Pilot reportedly required medical treatment and this was not a minor injury (weak laser) wound. More will come out to tomorrow as this story hits the print press.
Not much. The power of SDI was due to the size of the beams, not the necessity for overpowering the 'dissipation'...
If I remember correctly, the SDI LASERS were to be eight or twelve feet in diameter. Would you trust a 1 millimeter diameter beam to stop an incoming ICBM by punching pinholes in it? Probably not.
You're also not likely to get an eight or twelve foot diameter rod to lase at one Watt, given the required size of the flash source/chamber.
I resemble that remark.
Seriously, the air traffic co-ordination with stuff like GuideStar is nontrivial.
I hope this doesnt result in a bunch of idiotic legislation.
The pilot "saw" the laser, so apparently it was visible. Pity he didnt say what color, as that would narrow it down a bit.
No it's not. Oh some of it is scattering outside the direct path to the target, but if any signifigent amount were heating the air it would cause the laser to "bloom". That's part of the reason they need high power, but short pulses for SDI work. But even then, only a very small fraction of the laser energy goes to heating the air, although it's enough to disrupt the path. The short pulse gets through before the atmosphere has time to react to being heated.
The atmosphere doesn't absorb that much light. Sunlight is only attenuated by about half going through several miles of atmosphere.
If it did, you wouldn't be able to see mountains from 15 miles away.
Laser injures Delta pilot's eye
By Bill Gertz
THE WASHINGTON TIMES
===
A doctor who examined the pilot determined that he had suffered a burned retina from exposure to a laser device, the officials said.
Transportation Security Administration (TSA) spokeswoman Yolanda Clark confirmed the incident, but declined to provide details. "
There are some materials that become opaque at high intensity.
Silicon, for example, will experience 2 photon aborbtion resulting in the generation of free carriers which absorb. It happens quite fast.
Pity you can't see through silicon.
You're responding to a point I wasn't making. I was talking about the space heater laser comparison. The comparison was a conservation of energy comparison. Let me say it again: The heat energy dissipated by a laser traveling through 5 miles of atmosphere is almost certainly greater than the heat energy generated by a space heater. Even if you adjust the power levels and exposure times, I don't see it. As for the point you DID make, that was brought up by a different poster and yes, I can see that. You're basically saying that the laser energy and energy loss relation is not linear.
Off-point. I already addressed that in a previous post.
From his post, that's my understanding as well. But this would mean that 'low-power' lasers are EXCEPTIONALLY efficient in the atmosphere. Given the coherence of the light frequency I can buy that.
The thermal lensing aka blooming problem is likely a tractable problem using adaptive optics.
Or get'em in space where there is no atmosphere.
I was wondering the same thing. If it was green, it could have been an Argon Ion or a dye laser. If it was blue, it may have been a krypton. Red could be lots of stuff. Obviously, IR (CO2) are ruled out.
a bird of prey that can fire while cloaked?
That was only one of the SDI investigations. (IIRC, that worked).
The Air Force Airborne Laser uses a Chemical Oxygen Iodine Laser
Specs on the system:
Type : 6 COIL (Chemical Oxygen Iodine Laser) modules in series world's shortest wavelength, high-power chemical laser
Wavelength : 1.315 mm
Weight : 1.5 tons per module (6 modules on ABL)
Power : Megawatt class.
Range : several hundred km (when missiles emerge from above the clouds)
Aircraft : 747-400 commercial freighter
Altitude : 12,000 meters
Notice "Mega-Watt class" not 10^16 watts, only 10^6 Watts.
You may be right.
What?
Air doesnt ionize in the near IR until well into the gigawatt regime. I work at megawatt intensities in air all the time.
That level of energy is huge. You'd vaporize the pilot at those power levels...
No, it would make an annoying spark on his skin, like getting whacked with a rubber band (high peak power, not energy). Much lower levels than this will cause eye damage.
Argon Ion would do it as would doubled YAG (really nasty).
Obviously, IR (CO2) are ruled out.
I've actually experienced 1064 nm as a color, but this occurs at very dangerous retinal intensities where nonlinear processes start kicking in.
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