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Re: Meridional Distances
From: Peter Fogg
Date: 2002 Sep 18, 09:37 +1000
From: Peter Fogg
Date: 2002 Sep 18, 09:37 +1000
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