A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Eamonn Sparling
Date: 2019 Mar 5, 09:22 -0800
For the definition of FPoA, I visualise a vertical line (the projection of the FPoA on the earth) travelling westward and the GP of the sun also travelling westward with a North component of 1'/hr ('d'). They both merge as the GP hits the equator at the Spring equinox. I checked in this year's n. almanac and all seem to be on target!! My question is: Is GHA ARIES ever early or late for this appointment (like the sun over Greenwich) and is an adjustment/correction ever required to be made in the almanacs for this?
Regards Eamonn S.
53.3° N 06.3° W