Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!usc!cs.utexas.edu!sun-barr!newstop!sun!amdcad!amdcad!military
From: gwh@headcrash.Berkeley.EDU (George William Herbert)
Newsgroups: sci.military
Subject: Re: AMRAAM
Summary: Why it was done that way...
Message-ID: <1991Apr11.033444.4240@amd.com>
Date: 10 Apr 91 06:04:49 GMT
References: <1991Apr10.024102.20311@amd.com>
Sender: military@amd.com
Organization: UCB Open Access Computing
Lines: 42
Approved: military@amd.com


From: gwh@headcrash.Berkeley.EDU (George William Herbert)


In article <1991Apr10.024102.20311@amd.com> sdragoo@magnus.acs.ohio-state.edu (Stephen P Dragoo) writes:
>Can someone explain to me why the DoD thought that designing AMRAAM was such
>a great idea?  I understand the need for a fully active radar-guided AAM, 
>but please!  Putting it in a missile smaller than Sparrow is ridiculous.  If
>they weren't able to do it in an 8inch diameter missile, how are they gonna do
>it in a 7inch diameter missile?  Better to try to update a Sparrow, or

There were a whole bunch of good reasons.  The number one reason was
that the Sparrow was late 1950's technology.  Since then, we've gotten
just a bit better at building small radar systems.  In fact, the 7"
diameter AMRAAM seeker is _better_ than the Sparrow even if fired in
semi-active only mode (a la Sparrow).  Going to the smaller missile
increased range (same power motor, roughtly, but about 25% lighter missile).

Just look at computer technology's advances since then...or even police
radar guns ( 8-) or civilian maritime radar.  You can get a sub-$1000
radar set today that weighs less than 100 lbs and is as good as
million-dollar 1-ton fifties radar sets.  Advancing technology lets you
get equal or better performance out of a smaller package.

>Personally, I think a longer range IR seeker would do the job.  Think about it.
>With the wonders they're doing now with the 5inchers in Sidewinders, think of 
>what they could do with an 8incher in a Sparrow-type.

IR is attenuated pretty badly with range.  Besides, you'd have to go to
a telescope of some sort, which would cut down the field of view of the
seeker and then cause more misses in the terminal phase of flight...
IR is great inside of 12 miles (with current best systems).  Outside
that, use radar.

Besides which, it's a _whole lot easier_ to decrease the IR signature
of an aircraft than the radar signature... And if all your missiles are
IR only homing, then the baddies don't have to fool with
Radar-Absorbent-Material etc.  in their next generation fighters...

	[Speaking of decreasing signatures... :-) --CDR]
--
George William Herbert 	gwh@ocf.berkeley.edu  gwh@gnu.ai.mit.edu