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Subject: Re: Meridional Distances
From: Peter Fogg (ffive@XXX.XXX)
Date: Tue Sep 17 2002 - 19:37:22 EDT
Thanks for the opportunity of amending the below: '... have tables accurate to 2
decimal places for each minute of arc for Meridional Parts ... etc'
As to Meridional Parts, the 1984 Bowditch has tables for M PARTS to one decimal
place for each minute of arc, my 1983 'Norrie's Nautical Tables' has them to 2
decimal places. Its important to realize that different tables may be based on
different spheroid models, and thus give slightly differing values.
As to M DISTANCES, if Bowditch has them its news to me, and welcome news if they
have been calculated to minutes of arc.
Chuck Taylor wrote:
> >
> > Although I have tables accurate to 2 decimal places for the Meridional
> > Parts, the Meridional Distances come only in whole degrees, so need to
> > be interpelated for in-between values.
>
> Peter,
>
> Bowditch has tables of Meridional Parts to quite a number of decimal places.
> The method for computing distances using Meridional Parts is called "Mercator
> Sailing" and is also described in Bowditch.
>
> The introduction to the tables in Bowditch gives a formula for computing
> Meridional Parts. I have programmed this into a calculator. One could also
> program it into a spreadsheet. If memory serves me correctly (I'm away from my
> home library) there is a typo in the formula in Bowditch 95, but Bowditch 80/84
> Volume 2 has it right.
>
> Best regards,
>
> Chuck Taylor
> Everett, WA, USA
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