A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Jim Rives
Date: 2020 Jan 9, 13:25 -0800
I am trying to clear a series of 6 sun-moon lunars taken on 2 January. I have a best fit straight line throught the data and came up with what I think is a pretty good regression (but really don't know how good is good enough). Average LD 56.05, R^2 = .987, StdDev 1.7. In any case, I decided to pick a LD on that line coincident with a convenient time... exactly 1800z. And, I went into Stellarium to get the altitudes I needed for that time of the sun and moon. I read in a post on this subject back in June of last year that Stellarium builds in the refraction and weather related anomolies and those can be eliminated by switching the atmosphere off. I couldn't find out if the altitude that stellarium provides is geocentric or topographic (or from the surface of the earth as I understand the term). What I believe I need is to get the altitude with HP removed as well, as if at the center of the earth. Does anyone know the Stellarium settings I would need to use to be sure of that?
Then, so armed, I'll be ready to see how I did determining the local time on Cape Ann on Jan 2!