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From: tek@CS.UCLA.EDU (Ted Kim (Random Dude))
Newsgroups: sci.military
Subject: Re: Aegis vs. Dozen Missiles (was USS IOWA)
Message-ID: <1990Jun29.025254.6265@cbnews.att.com>
Date: 29 Jun 90 02:52:54 GMT
References: <1990Jun20.043246.17762@cbnews.att.com> <1990Jun20.232933.1779@cbnews.att.com> <1990Jun22.043119.27816@cbnews.att.com> <1990jun26.025008.15408@cbnews.att.com> <1990Jun28.025720.18921@cbnews.att.com>
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From: tek@CS.UCLA.EDU (Ted Kim (Random Dude))

In article <1990Jun28.025720.18921@cbnews.att.com> bxr307@csc.anu.oz writes:
> ...
>Surely a better determinant of rate of fire of a missile launcher
>using a semi-active guidance system that the Standard missile does is
>the number of missiles that can be guided at the same time towards a
>target?  

Normally that would be so, except the SM2MR (and the ER) are not purely
Semi-Active Radar Homing missiles (though they can be fired that way).
The SM2MRs are use a two-phase guidance system. In the initial phase,
they use inertial guidance with midcourse correction updates. Only in
the final few seconds, are the missiles using SARH. The midcourse
corrections are encoded in the tracking radar signal from the SPY-1.

>It might be fine for you launcher to be able to fire missiles off
>wily-nily, however how much good is that when only the first two or
>three are actually able to be guided to their targets? Added to that
>must be the problem of at what ranges the engagements begin, because 
>the longer the missile is in flight, the longer it has to be guided
>and that cuts down the number of missiles that can be launched in a
>single engagement.  

The Aegis cruisers carry four Mk99 weapon directors. So four missiles
can be in terminal SARH, while others are in flight. The book "Modern
Naval Combat" by Chris & David Miller claims the number of missiles in
flight not in SARH can be as high as 18. That's probably under very
favorable conditions, but I think the point is made.

>I don't know how good the radars on the Aegis system are (and after
>the Iranian A300 episode I wonder even more) but I would doubt if
>more than two or four missiles could have handled in one engagement
>at any one time.  

At the risk of moderator editing, I don't think the SPY-1 radar was
proven to be faulty in the Iranian Airbus tragedy. IMHO, it was more
that the ship was placed in a situation it was not designed for, the
and that the IFF procedures were inadequate.   

-ted

Ted Kim                           
UCLA Computer Science Department  Internet: tek@penzance.cs.ucla.edu
3804C Boelter Hall                UUCP:    ...!{uunet|ucbvax}!cs.ucla.edu!tek
Los Angeles, CA 90024		  Phone:   (213) 206-8696