NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Robin Stuart
Date: 2016 Oct 16, 08:00 -0700
Herbert,
I've been travelling for the last couple of days. Thanks for clarification. It seems to me that the adjustments in the NA may do more harm than good. Unadjusted values on the hour would permit accurate linear or non-linear interpolation to be performed. The current tables mean that the user can never be sure of what the GHA of the Sun is to the nearest 0.1' at any time of the year. Overall it might be better if the NA made no adjustment and published a v correction for the Sun which you could choose to ignore.
The thought did occur to me that the adjustment could be done by minimizing the root-mean-square difference of the true GHA from that obtained for each second in the hour using the Almanacs Increments and Corrections tables (including all the warts mentioned by Sean and Stan).
Regards,
Robin Stuart
PS My recent sojourn took me to the New Bedford Whaling Museum which has a diorama depicting the Charles W. Morgan in action, a half size model of a whaling ship and this guy
