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NNTP-Posting-Date: Mon, 12 Jan 2009 08:33:47 -0600
From: "Jon" <jon8338@peoplepc.com>
Newsgroups: alt.math.recreational,alt.sci.math,alt.sci.physics,japan.sci.math,sci.math,sci.physics,soc.religion.quaker,uk.rec.psychic
Subject: Returning Fire: Vector Calculus
Date: Mon, 12 Jan 2009 09:32:55 -0500
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Xref: news.ccsf.jp japan.sci.math:161

A shot is fired and 3 microphones intercept the conical shock wave.  With 
electronics the arrival time differences between microphones is obtained. 
From the coordinates of the 3 microphones and the arrival time differences 
between them, the location of both the source and destination of the 
projectile is determined.

http://mypeoplepc.com/members/jon8338/math/id22.html

The solution is independent of the speed of the bullet.  Two shots in the 
same direction but at different speeds still originate from the same source.

I posted about this problem before, but after applying it with data I 
corrected several mistakes and streamlined the process.  The web page above 
has a link to an Excel 97 workbook that utilizes Least Squares to solve a 
matrix and Excel's Solver to find the root to a quartic with 100 iterations.