A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Position-Finding
From: Geoffrey Kolbe
Date: 2018 Feb 10, 06:36 -0800
The Bygrave equations are basically a re-writing of the standard equations of spherical trigonometry. There are plenty of books which derive the standard equations of spherical trig and any number of online sites too. Once you are happy you understand how the standard equations of spherical trig are derived, I can show you how to go from there to the Bygrave equations.