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At my web page my article:
"Celestial Fix Nautical Almanac Sight Reduction algorithm for n LoPs", gives a 
detailed information of the algorithm.

Originally the references are:
* Optimal Estimation of a Multi-Star Fix, C. De Wit. NAVIGATION, Vol.21 , No. 4, Winter 1974-
75, pp 320-325
* Compact Data for Navigation and Astronomy for the Years 1991-1995, Cambridge University
Press ISBN 0-521-38731-0. Yallop B. D. and Hohenkerk C. Y. (1991).
* The Nautical Almanac. USNO

Also the free program "CelestialFix.exe" implements the method, see pic.

Regards,

Andrés Ruiz
Navigational Algorithms
https://sites.google.com/site/navigationalalgorithms/


-----Mensaje original-----
De: navlist-bounce@fer3.com [mailto:navlist-bounce@fer3.com] En nombre de Gary LaPook
Enviado el: jueves, 18 de febrero de 2010 11:41
Para: NavList@fer3.com
Asunto: [NavList] Re: Advancing LOPs for precision fixes

Have you tried using the method in the N.A. to which you refer? I may be 
missing something but I don't see anywhere in the given formulas where 
you input course and speed which would be necessary if the method was 
allowing for advancing the LOPs to a common time.

gl


P H wrote:
> As John Karl writes in his book:
> "The Nautical Almanac gives an iterative procedure for calculating a 
> fix from several intercepts and azimuths determined from their St. 
> Hilaire sight reductions."
>
> I would add that this procedure does take the vessel motion (assumed 
> to be constant during the round of observations) into account.  I am 
> confident that I am simply restating a fact that is well-known among 
> NavList members.  Also, I think it is not unreasonable to assume that 
> the content of the Nautical Almanac reflects common (standard, 
> recommended, accepted, etc.) practice.
>
>
> Peter Hakel
>
>
> ------------------------------------------------------------------------
> *From:* hch 
> *To:* NavList@fer3.com
> *Sent:* Tue, February 16, 2010 8:20:41 AM
> *Subject:* [NavList] Re: Advancing LOPs for precision fixes
>
> Gary,
>  
> You said ... "It is common practice to ignore the movement of the ship 
> during the time period needed to take a round of sights ...", and I 
> am unable to dispute this assertion in the light of today's "it's good 
> enough" approach to Celestial Navigation. I can, however, state in no 
> uncertain terms that this was not the traditional approach - LOPs 
> generated in a round of sights were always advanced or retarted to a 
> common time, so long as the distance run between individual sights was 
> measurable, if for no other reason than professional pride.
>  
> Regards,
>  
> Henry
>
>

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