NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Historical Lunars : take in account 'delta-T' or ignore it ?
From: Frank Reed
Date: 2009 Dec 23, 10:54 -0800
--
NavList message boards: www.fer3.com/arc
Or post by email to: NavList@fer3.com
To , email NavList+@fer3.com
From: Frank Reed
Date: 2009 Dec 23, 10:54 -0800
Antoine, you asked:
"Am I right in guessing that the formula given hereabove - cos^2(position angle) - is one parametric formula (among a few others) to define exactly an ELLIPSE ? Such an ellipse would have its semi-major axis horizontal and (almost) equal to semi-diameter, and its semi-minor axis vertical and equal to half the distance between apparent refracted upper and lower Limbs ?"
Yes. Just that simple. We parametrize it in terms of position angle because that can be counted as an observable parameter.
-FER
NavList message boards: www.fer3.com/arc
Or post by email to: NavList@fer3.com
To , email NavList+@fer3.com