NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: That darned old cocked hat
From: George Huxtable
Date: 2010 Dec 10, 18:47 -0000
From: George Huxtable
Date: 2010 Dec 10, 18:47 -0000
Kermit wrote- "DANIELS mentions a fascinating point explained in "Admiralty Navigation Manual (1947)" where it is proven that [in the case of 3 observations] the probability for the actual fix to lay inside the cocked hat is only 0.25 ." Here's a section from an even earlier Admiralty Manual of Navigation, from vol. III of 1938, pages 165-166. It deals, not with astronomical LOPs, but the analogous situation of a cocked hat constructed from three bearings to coastal landmarks. And it doesn't offer a proof, just an assertion. But it's our familiar value of a probability of 0.25 of being inside the triangle. George. contact George Huxtable, at george{at}hux.me.uk or at +44 1865 820222 (from UK, 01865 820222) or at 1 Sandy Lane, Southmoor, Abingdon, Oxon OX13 5HX, UK.