NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Refraction affects interstellar angles
From: Paul Hirose
Date: 2002 Feb 19, 10:55 -0800
From: Paul Hirose
Date: 2002 Feb 19, 10:55 -0800
Chuck Griffiths wrote: > > stars are located at the same altitude. I got the idea most recently from both > "The Sextant Handbook" by Bruce Bauer and "Celestial for the Cruising Navigator" > by Merle Turner. I also vaguely remembered the Ocean Navigator article Those authors may have picked up their misconceptions from Bowditch. Describing a test for centering error, my 1984 edition of Vol. 1, in Art. 1509, "Sextant adjustments", says, "An alternative method is to measure angles between the lines of sight to stars, comparing the measured angles with computed angles. To minimize refraction errors, one should select stars at about the same altitude, and avoid stars near the horizon." -- paulhirose@earthlink.net (Paul Hirose)
