NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Out of Date Almanac
From: Frank Reed
Date: 2009 Dec 7, 18:27 -0800
From: Frank Reed
Date: 2009 Dec 7, 18:27 -0800
Greg, you wrote: "my plan is to use a 2006 for the upcoming year 2010." You can use a four-year-old Nautical Almanac for the Sun and stars with only small errors. For the Sun, the errors are only a couple of tenths of a minute of arc. For the stars, unless you apply parallax corrections (and then what's the point? might as well get a new one), the errors can be as large as 1.5 minutes of arc but typically less. It's no good for the Moon and planets, of course. The other almanac tables for interpolation, refraction, site planning, etc. do not change from year to year, so it's certainly worth grabbing an old one for those. Another option for the "ephemeral" data would be to print out the pages you need from an online nautical almanac. There's mine: http://www.historicalatlas.com/lunars/nadata_v5.html and there's one by Omar Reis: http://www.tecepe.com.br/scripts/AlmanacPagesISAPI.isa which is formatted just like the official Nautical Almanac. -FER -- NavList message boards: www.fer3.com/arc Or post by email to: NavList@fer3.com To , email NavList+@fer3.com
