NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Henning Umland's spreadsheets.
From: Bill Lionheart
Date: 2018 Apr 9, 02:20 +0000
From: Bill Lionheart
Date: 2018 Apr 9, 02:20 +0000
Next month I am sailing from St Lucia to Bermuda and then to NY on a friend's yacht (lucky me!) . I said I would show the crew some simple celestial navigation, and it is a grat chance for me t practice sextant work myself with I hope clearer sky than I am used to! I currently use my own rather eccentric python scripts using the ephem library but I wanted to show them sight reduction on spreadsheet so I went back to Henning Umland's excellent spreadsheet "Sun and Moon Almanac V1.51 for the Years 1975-2015" It seems the version I have has a hard coded limit on the year as it does not have this year's delta T, and I think the one on Henning's web site has not been updated. It is an easy matter to edit the javascript to update Delta T, but I may be reinventing the wheel here, perhaps someone has a version working for 2018 already? (we had an earlier discussion of a java script bug, due to a change in the trunc function in java script as I remember, but that was a few years ago). Best wishes Bill Lionheart
