Using Mylar to reflect laser pointers light into flight cockpits

Discussion in 'General Science & Technology' started by cosmictraveler, Jun 1, 2011.

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  1. cosmictraveler

    cosmictraveler Be kind to yourself always.

    Could a thin film of Mylar be used to stop laser pointers from being used to blind pilots that are flying aircraft? By adhering the see through film onto the inside of cockpit windows they could prevent the laser light from harming anyone and its cost is very small.
     
  2. billvon

    billvon Valued Senior Member

    If you block all the light the pilots can't see. If you block some of the light it makes it harder to see at night. If you don't block any of the light visibility is ideal, but it offers no protection against lasers.
     
  3. Echo3Romeo

    Echo3Romeo One man wolfpack

    It would make more sense to use something like a polarizer, but then, it would still affect visibility because you're attempting to attenuate visible light. Canopies on aircraft are sometimes treated to block out IR and UV to reduce cockpit heat, and block IR lasers and solar UV rays.

    I'm not aware of the use of tinted canopies for blocking visible light. Some military aircraft have a gold colored tint on their glass, but that's a layer of actual gold put there to keep out RF from external ECM gear and the like.
     
  4. Stoniphi

    Stoniphi obscurely fossiliferous

    Source auto-tracking and returning fire may help too. I would consider attempting to blind me - especially while I was flying an aircraft - to be an unprovoked hostile attack and would prefer to respond accordingly.

    I have given persons who pointed a laser pointer at my face a rapid learning experience and strong negative reinforcement for doing that with 100% compliance thus far. I think that shooting anything at aircraft or automobiles etc to be a tad sociopathic, considering that the perpetrator does not know the victim and the intent is hostile.

    Yes, I am aware that some of you will strongly disagree with this...and I don't really care about that.
     
  5. leopold

    leopold i miss my coco.

    shining the light from laser pointers into the cockpits of aircraft is a federal offense in my area.
     
  6. billvon

    billvon Valued Senior Member

    Even if that were technically possible (which it currently isn't) hitting someone with a 10mW laser on the ground isn't anywhere nearly as problematic as hitting someone with a 10mW laser who's trying to land an airplane at night. Taking 10 minutes to recover your night vision is a much bigger problem for the pilot.

    "Never attribute to malice that which is adequately explained by stupidity." - Hanlon's Razor
     
  7. cosmictraveler

    cosmictraveler Be kind to yourself always.

    But using this reflective film will prevent any injuries from happening if lasers are used at pilots. They could make it in the form of a roll down shade to use only at night so they don't have to adhere it to the actual window permanently.
     
  8. GeoffP

    GeoffP Caput gerat lupinum

    Even cheaper solution: Mylar goggles or sunglasses.
     
  9. adoucette

    adoucette Caca Occurs

    Do you have knowledge of this ever being a problem?
     
  10. Echo3Romeo

    Echo3Romeo One man wolfpack

    Awkward, inelegant, and ineffective. Imagine the aircrew scrambling around the cockpit pulling down flimsy mylar blinds after the laser beam has come and gone, while they would otherwise be concentrating on their takeoff/landing.

    Going the polarizer route again, you could use liquid crystals in the glass as an adjustable polarizer, like LCD monitors do. (See also: smart glass.) The polarization of the window glass could be adjusted to attenuate incident light beyond a critical angle (like the ground under the aircraft) but let almost everything else through. The current through the glass would change the polarization angle, and could be controlled by a microprocessor slaved to photodetectors around the windows and the outside of the aircraft. You'd have a response time measured in milliseconds and it would be completely automated, allowing the aircrew to concentrate on landing the plane. No moving parts to break, either.
     
  11. leopold

    leopold i miss my coco.

    the blink response of the human eye is not fast enough to protect you from laser light.
    i seriously doubt if "pulling down shades" will be any faster.

    i like the "LCD" idea. right where the beam strikes the window the crystals immediately darken blocking any penetration.

    you might even be able to get some kind of range for an accurate GPS origin of the source.
     
    Last edited: Jun 3, 2011
  12. Stoniphi

    Stoniphi obscurely fossiliferous

    The 'smart glass' concept is the best so far IMHO, especially considering that this is all light of a very specific wavelength.

    Guess I am more intimidated by the US military and contemporary technology than you are, Billi. :eek:

    Also, the damage from laser light is permanent - it kills the photoreceptor cells it hits. That 'recovery' is a wetware compensatory response.
     
  13. cosmictraveler

    cosmictraveler Be kind to yourself always.

    The pull down shade would be pulled down while the craft is high in the air away from the ground before it gets near a city. They can still see through it but it would reflect the laser light so no one gets harmed.
     
  14. leopold

    leopold i miss my coco.

    it's also accumulative, lesser and lesser "doses" will affect you more.
     
  15. billvon

    billvon Valued Senior Member

    So pull down a light-reducing shade at night just before the one portion of the flight where night vision is most critical?
     
  16. Stoniphi

    Stoniphi obscurely fossiliferous

    OK, hows about we just switch to that proposed SCRAM jet design that has no windows at all - just exterior video feeds to flat screens. Retrofitting would be expensive, but cheaper than having our dwindling supply of pilots go blind IMHO.
     
  17. cosmictraveler

    cosmictraveler Be kind to yourself always.

    The crews are using INSTRUMENTS when landing at night so they really don't need to "see" what landmarks are outside the plane. The mylar is coated with tint on the one side and a mirror on the other so that the crew could still "see" outside but it would be a little darker is all. This material won't obscure what the crew is seeing at all.
     
  18. Echo3Romeo

    Echo3Romeo One man wolfpack

    Hmm...

    edit: To be less snarky, you just need to acknowledge that attenuating VISIBLE light entering the cockpit will result in less VISIBLE light hitting the pilot's retina, which means less will be VISIBLE to him/her. There's no way around that.

    To expand again on the smart glass idea, you might be able to build both the polarizer and the photodetector into the window itself. If that were possible then pixelating it would be, too. Then the glass would be able to selectively darken the precise area the laser beam was striking it, leaving other parts of the glass clear. The same way an LCD monitor shutters out the backlight, basically. Assuming manufacturing the windows in such a way is possible it wouldn't be difficult to connect the windows to a microprocessor so that as a laser beam zipped across the glass, the pilots would only notice the little pixels in the glass flicking from clear to dark to clear again. (If it happened slow enough for them to notice at all.)
     
    Last edited: Jun 5, 2011
  19. Stoniphi

    Stoniphi obscurely fossiliferous

    I like that concept, it seems doable. Now for the implementation.....
     
  20. adoucette

    adoucette Caca Occurs

    Well it depends on the power of the laser, the color of the light and the distance between the laser and the retina.

    I think that it's nearly impossible for any commercially available laser to cause permenant eye damage to a pilot of a jet from someone shining the laser from outside the airport boundaries. Indeed, without a much more powerful laser coupled with a sophisticated tracking system it would not be possible to keep the laser targeted on a cockpit of a moving jet at a reasonable distance for more than a second or so.

    The most powerful laser a consumer can legally buy is 1 watt, but it has a divergence of .0005 radians and thus would be a "spot" ~40 cm wide at 1/2 mile, with a power density way too low to cause any damage (it would be very bright and very distracting, but not able to damage retinal tissue)

    http://www.wickedlasers.com/lasers/Spyder_III_Pro_Arctic_Series-96-37.html

    Indeed, it is nearly impossible to damage eye tissue with Class 3a lasers (up to 5 milliwatts) when used in the same small room.

    http://www.science.sjsu.edu/nucsci/pdf files/250120498.pdf

    Arthur
     
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