NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Ed Popko
Date: 2018 Apr 6, 07:12 -0700
John Luykx, a frequent contributor to The Navigator's Newsletter (no longer in print), wrote a three-part series on Determining Longitude by Lunar Distance Observation. In this well-written series, he provides sample clearing solutions and computation of longitude from the same lunar observation using DeLambre's and Jean Borda's methods. Attached is this part-three article.[1]
This is a nice set of examples and the first time I had seen a correction factor for the Moon's Oblateness when correcting the moon's apparent to observed altitude (see page 14, step 21)
For this lunar observation, the correction is not much and not likely to make any difference to the cleared distant result but since I'm noticing this for the first time, do any other NavList lunarians use this altitude correction?
Ed Popko
[1] John M. Luykx, "Determining Longitude by Lunar Distance Observation: A Sample Solution", History of Navigation, The Navigator’s Newsletter-Foundation for the Promotion of the Art of Navigation, Issue Fifty-Six, Summer 1997, pp.14-17
