Juvat wrote in message . ..
Tom Cooper posted:

BTW, from what I know a USAF Lt.Col. who was in the back-seat of the IIAF
RF-4E ...used photo-flash cartriges to decoy four R-13s:

Really? By 1980 no photo-flash cart in the USAF would have done that,
wrong band of the IR spectrum...versus the IR seeker's spectrum. Thank
goodness for early generation technology theft.


I can not comment on the story of photo-flash carts being used to
defeat any seeker. I imagine it would work, I see no reason it should
not, but as I am not familiar with the burn times or dispense patterns
of the cartridges I can only guess. My comments are aimed more at the
comment about "by 1980 it could not have worked".

While I can see that photo-flash stuff would be tailored to emit the
most energy in the optical band of interest, it is very hard, some
would say impossible, to design such a device that did not also emit
in unwanted bands. An example is the modern IR countermeasures flare.
Lets say the MJU-49B.

http://www.globalsecurity.org/milita...ems/mju-49.htm

This flare is tailored to put most of its energy out in the threat
bands of interest. The page above claims 2 to 5 micrometers. This
encompasses both the near IR and the mid IR bands. Or, both uncooled
and cooled PbS detector systems. The response curves of PbS (and
other detector responses) can be found he

http://www.electro-optical.com/bb_rad/detector.htm

Despite the fact that the MJU-49B is tailored, specifically made, to
emit most of its energy in the near and mid IR bands, a significant
portion of energy is still emitted in the visible portion of the
spectrum (shorter wavelengths). And, it is easier to tailor towards
the longer waves, than it is to do so towards the shorter waves, such
as the visible band. The band of emission is tied loosely to heat
energy, less energy, longer wavelengths. Or, less heat, longer
wavelengths.

Still, the point is that flares tailored to work in the IR spectrum
still, very often, possibly even always, emit in the visible spectrum
as well.

http://www.warforum.net/gallery/disp...=lastup&pid=61

So, my question is, why could photo-flash cartridges used by the USAF
in 1980 NOT have served as an stand-in IR countermeasures flare? Has
it something to do with the fashion of dispense? Do they not light
until well away from the aircraft? Or am I missing something more
obviouse here?

Token