Re: in laser guided bombs, the receptor/photodetector

On Feb 18, 5:07 am, Alan Dicey <a...@xxxxxxxxxxxxxxxxxxxxxxxxxxx>
wrote:
extremewanderer wrote:
On Feb 15, 10:15 pm, Alan Dicey <a...@xxxxxxxxxxxxxxxxxxxxxxxxxxx>
wrote:
extremewanderer wrote:
All that is needed to reflect the laser is just air, only air.
As per the fig 2 below, the spot of light is hanging in air in front
of the target.
 Fig 2
  ------------------------------------------------------O {}
 In fig 2, dashed line is laser beam, the brackets represent the
 target, the circle represents a spot of light in front of the target
 which does NOT NEED TO TOUCH THE TARGET and then bounce of in order
 to be detected.- Hide quoted text -
- Show quoted text -
I know this sounds physically impossible, but it is not.
Provide Proof or Retract- Hide quoted text -

- Show quoted text -

This is how;
A spot of light is formed due to the intersection of two laser beams.

No.

Laser beams are electromagnetic, they may be aimed so as to coincide but
  they do not affect one another and each continues on its way as though
nothing had happened - because nothing has.

Point of yellow colour will be formed due to colour mixing of green &
red.

A yellow colour would be formed by the additive mixing of green and red
light.  But you must have something at the intersection to reflect the
light, or the effect won't be visible, mixing will not happen.

This colour mixing does happen, I have inquired from a manufacturer of
show lasers.

You could always have looked up a junior school science text book, where
additive mixing is usually covered.  Doesn't have to be lasers.

Colour mixing will be like it happens in tvs.

I assume you mean televisions.  No, it won't.  Because : -

1) in a TV tube there are no laser beams or light beams of any kind.
There are scanned beams of electrons, subatomic particles, traversing
the vacuum inside the tube, that are arranged to strike dots of
electroluminescent phosphors coated onto the inside of the glass screen:
  each phosphor glows red, green or blue when stimulated by electron
bombardment.  The viewer is far enough away from the screen that they
cannot see the individual dots.  I can find no way in which this
resembles anything you have described up to now.

If you mean a flat screen of some kind, there are still no lasers
involved, and the dots are still electroluminescent emitters, but the
means of stimulus is  by direct addressing of the dot through electronic
switching.

AND

2) because you say

Except, here there is no screen, the colour mixing is happening in
air.

A screen, or some means of reflecting or scattering the incident light,
is an essential part of a light mixing system (my familiarity comes from
stage lighting, where the actors and set are the reflectors).  Without
the reflection there is no mixing:  no rays of light will be reflected
along congruent paths to the sensor to be received simultaneously and
perceived as "yellow".

To drag this back onto something resembling the topic:  you're proposing
to eliminate the need to reflect the designating laser beam from the
target by instead reflecting it off another laser beam (by some means as
yet unexplained), some distance away from the target.

What advantage does this give?

I think it might help if you told us what your level of familiarity with
optical physics is, on a scale from infant school to PhD?  We can then
adjust our explanations to eliminate anything you already know.- Hide quoted text -

- Show quoted text -

Ok, I have a question related to optical physics, with reference to
the text below,
"The "Tribute in Light" memorial as seen from Bayonne, New Jersey,
consists of two shafts of light to
represent the World Trade Center Twin Towers, in New York City."
Here, why are the shafts of light visible from a distance?
Are some reflectors being used?
Are any contaminants, "(water, dust, smoke) in the air to
maintain their visibility", being used?
The shafts of light are aimed at the sky, then Why are they visible?
Does this mean that scattering of light is happening?
.

Relevant Pages

  • Re: in laser guided bombs, the receptor/photodetector
    ...  target, the circle represents a spot of light in front of the target ... electroluminescent phosphors coated onto the inside of the glass screen: ... A screen, or some means of reflecting or scattering the incident light, ... to eliminate the need to reflect the designating laser beam from the ...
    (rec.aviation.military)
  • Re: in laser guided bombs, the receptor/photodetector
    ... target, the circle represents a spot of light in front of the target ... There are scanned beams of electrons, subatomic particles, traversing the vacuum inside the tube, that are arranged to strike dots of electroluminescent phosphors coated onto the inside of the glass screen: each phosphor glows red, green or blue when stimulated by electron bombardment. ... A screen, or some means of reflecting or scattering the incident light, is an essential part of a light mixing system. ... To drag this back onto something resembling the topic: you're proposing to eliminate the need to reflect the designating laser beam from the target by instead reflecting it off another laser beam, some distance away from the target. ...
    (rec.aviation.military)
  • Re: in laser guided bombs, the receptor/photodetector
    ...  target, the circle represents a spot of light in front of the target ... A yellow colour would be formed by the additive mixing of green and red ... electroluminescent phosphors coated onto the inside of the glass screen: ... to eliminate the need to reflect the designating laser beam from the ...
    (rec.aviation.military)
  • Re: in laser guided bombs, the receptor/photodetector
    ... instead of reflecting the laser beam, absorbs it and the laser beam ... does not reflects off /bounce back from the target, so the detector ... can't see the target. ...
    (rec.aviation.military)
  • Re: in laser guided bombs, the receptor/photodetector
    ... On Jan 29, 12:54 am, Juergen Nieveler ... instead of reflecting the laser beam, absorbs it and the laser beam ... can't see the target. ...
    (rec.aviation.military)