Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!uwm.edu!linac,att!cbnews!cbnews!military From: jjb%sequent.uucp@RELAY.CS.NET (Jeff Berkowitz) Newsgroups: sci.military Subject: Shooting Down Cruise Missiles Keywords: cruise missile Message-ID: <1991Mar19.043130.6859@cbnews.att.com> Date: 19 Mar 91 04:31:30 GMT References: <1991Mar14.014808.18265@cbnews.att.com> Sender: military@cbnews.att.com (william.b.thacker) Organization: Sequent Computer Systems, Inc. Lines: 49 Approved: military@att.att.com From: Jeff Berkowitz During the war a CNN team was taken by the Iraqis to visit a site that had been bombed. While they were there, outdoors (USAF had converted most of the indoors into outdoors, no :-) several cruise missiles flew overhead. The CNN camera crew filmed it; I'm sure many of you saw. At first this seemed impossibly unlikely. In a country the size of North and South Dakota the film crew is standing outside, and all these missiles fly over!? After a little thought, though, I decided it was not so unlikely. Note: I've never held a security clearance or worked on a weapons system of any type, certainly not cruise missiles...what follows is speculation. As explained in this group, the Tomahawk spends most of its time on a conventional inertial navigation system. Periodically, it corrects the inertial "fix" by comparing a simple terrain map (altitude only) with measurements from a radar altimeter. It then corrects its inertial "fix" and continues to the next "map correction area", etc. Depending on the quality of the inertial nav unit, only a few areas along the way will need to be terrain mapped. Now consider the special nature of cruise missile flight planning. There's no point in conserving fuel. The weapon is only for use against stationary targets, so there's no hurry. There's no reason to take the shortest path to the target! Finally, let's speculate that making up terrain maps is a lot of work, especially under the time pressure that preceded the outbreak of hostilities in the Gulf. What this all means is that the people who programmed the missiles probably concentrated on finding the smallest number of common paths that lead from all the launch areas to all the targets. Specifically, they identified the smallest number of appropriate areas for terrain corrections, and routed all the missiles across these areas. If a Tomahawk is ever observed, the point of observation is a very likely place to shoot down future missiles. This is a definite weakness in the weapons system. Since the pulse jet engine probably makes a characteristic noise, human observers can be taught to report the passage of the missiles. Air defence radars can then be concentrated in these areas. Once detected, Tomahawk is vulnerable to conventional techniques, like interceptors and tactical antiaircraft missiles; it's not even supersonic. Mmmmm.... -- Jeff Berkowitz N6QOM uunet!sequent!jjb | If you can't trust the comics, Sequent Computer Systems jjb@sequent.com | what can you trust? -Bullwinkle