A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: William Porter
Date: 2018 Oct 31, 14:35 -0700
Thank you Frank; that's immensely helpful. I have found your site in the past but not your lunar tool. So using your calculator one of my worst sights proves out to 0.3', eliminating observation error as an explanation. The error I HAVE found is odd: my GHA of Altair appears to be wrong. I am probably making a basic error converting from RA so I will be back. The lunar-specific corrections seem to be correct. Thank you again.
Haversines because I have always used them (and tables) to eliminate all technology from the boat bar the chronometer. Lunars are the obvious last step. I am pretty familiar with haversines and of course check the results in the spreadsheet using more "cos". But a haversine is not that arcane a trig function, as you know...