NavList:

Thank you George for your clarification in your Post [NavList 14748] . Nice to know that the referenced article covered coastal bearings.

Also I would like to thank you here John for your just magnificent explanations in your next to last post [NavList 14746]. Thanks for replying to my query about the probability numbers tagged to each ellipse. From my Engineer background, I feel - but just unfortunately "feel" - like your method is a most correct one. The numerical values you gave us were earlier numericaly integrated, OK (ref your first post on our subject) ? Do you have any other different numerical integration algoritm to fully confirm your numbers ?

And to the attention George Brandebourg, I also see a definite interest in your suggestion to compute a " three-fold, probability-weighted integration over all possible locations of the three LOPs ". Still I am under the impression that John already did such a numerical integration and has shown his own results (Ref his 1 st post, and my remark just above) . But certainly John you will confirm or infirm this point.

To all souls on-board ... if anyone has got more ideas ... please go for it, i.e. send us a note on NavList.

And BTW ... Frank ... are you here ??? :-)))

Kermit

Antoine M. Cou�tte

*******************************************************************************

[NavList] Re: That darned old cocked hat
From: george---me.uk
Date: 10 Dec 2010 18:47

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.

----------------------------------------------------------------
NavList message boards and member settings: www.fer3.com/NavList
Members may optionally receive posts by email.
To cancel email delivery, send a message to NoMail[at]fer3.com
----------------------------------------------------------------