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From: urbanf@yj.data.nokia.fi (Urban Fredriksson)
Newsgroups: sci.military
Subject: Re: Soviet helicopters
Keywords: Soviet,helicopters,jammers
Message-ID: <1991Jan24.041934.23995@cbnews.att.com>
Date: 24 Jan 91 04:19:34 GMT
References: <1991Jan22.014806.19572@cbnews.att.com>
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From: urbanf@yj.data.nokia.fi  (Urban Fredriksson)
u870234@daimi.aau.dk (Anton Norup S|rensen) writes:



>From: u870234@daimi.aau.dk (Anton Norup S|rensen)
> In connection with these choppers, I have read about IR-jammers. How do these    work? I find the name a little strange, as I associate jamming with radio-
>frequencies only...

Most IR missiles uses scanning seekers (something like a telescope),
and never get an image of the target, only relative signal strength
when the seeker points in  (very slightly) different directions.

Under ideal conditions, you get maximum signal when the seeker is
pointing straigth at the target, but with at pulsing jammer you
just might be able to get the seeker to record maximum signal when
it's slightly off-angle, thus you fool it to turn in the wrong
direction. I guess the pulsing had better be matched to the
scanning period.   

       - Urban
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