A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Marcel Tschudin
Date: 2005 Aug 4, 13:48 +0300
While searching with Google, I came across this mail list. May be some one out here may be able to help me answering the following question:
How do refraction values for negative elevations have to be calculated, such as e.g. the horizon from a plane? (I am interested in the range of 0° to approx. 5°.)
Is Bennetts approximation also valid for negative elevations? If not, what other approximation formulae should be used, or, where can one find some benchmark values?
I am interested in formulae for both, refraction from apparent position and from physical position.
Thank you for any input to my problem.