NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Plumb-line horizon vs. geocentric horizon
From: Frank Reed CT
Date: 2005 Feb 10, 22:23 EST
From: Frank Reed CT
Date: 2005 Feb 10, 22:23 EST
Jim T wrote:
"Are the Nautical Alamanc's
data referenced to the earth's ellipse, or to a model based on the geoid?"
data referenced to the earth's ellipse, or to a model based on the geoid?"
Hmmm. FWIW, they're based on the celestial sphere. The Earth's oblateness
is accounted for separtely via the usual (small) oblateness corrections for the
Moon's parallax e.g., and via changes in plotting (the size of a minute of
latitude).
-FER
42.0N 87.7W, or 41.4N 72.1W.
www.HistoricalAtlas.com/lunars
42.0N 87.7W, or 41.4N 72.1W.
www.HistoricalAtlas.com/lunars
