A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Robin Stuart
Date: 2021 Nov 28, 09:52 -0800
In the attached spreadsheet I calculated the adjustment for the Sun's changing declination using the method outlined here http://fer3.com/arc/m2.aspx/Longitude-Equal-Altitudes-Stuart-jul-2020-g48277 and agree with your result of 32.8'W for your longitude. That's good but probably not too good to be true. My own forays into equal altitudes produced results within 0.3' in longitude (although I was averaging over 12 sights).
Earlier investigations on the accuracy that can be obtained for longitude can be found at