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A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: 3 Lop's
From: Geoffrey Kolbe
Date: 2004 Nov 15, 07:52 +500
From: Geoffrey Kolbe
Date: 2004 Nov 15, 07:52 +500
Alex wrote:- >Some books consider finding a fix from 3 lines >of position. This case also popped up in our infinite >discussion of the Averaging. >Can anyone explain, under what circumstances one could >possibly want to determine her position from 3 LOP's? >It is hard to imagine (for me) such circumstances. >(Hard but possible). >Alex. It is only with 3 LOP's that you can create a cocked hat :) Seriously though, 4 LOP's, with azimuths approximately 90 degrees apart, are better than two. The 4 LOP's would create two sets of "tram lines" at right angles to each other. The 4 LOP's are reduced to two by bisecting each set of tramlines. Your position is now uniquely defined by the intersection of these two LOP's. The advantage of this procedure is a reduction, if not complete elimination, of errors in dip or index error. Geoffrey Kolbe