A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Arthur Pearson
Date: 2002 Mar 22, 13:11 -0500
It is invaluable to have a circle of colleagues with whom to compare notes. I have put Chuck's lunar into my spreadsheet using the average watch time, Ds, and time-adjusted altitudes as listed by Bruce below. With the benefit of comparing my results to Bruce's, I was able to find several gross errors in my spreadsheet. Once corrected, I came up with a GMT for the time of observation of 00:18:15, March 19. This is 35 in advance of Bruce.
My intermediate results were as follows:
Sa: 7* 5.'7
Ma: 44* 29.'7
Moons R&P: 38.'45
Venus R&P: 7.'28
Moons Augmented SD: 15.'18
D, the cleared distance: 38* 43.'2
The only material difference in our approach I am aware of is that I am using augmented SD of the moon to reduce the sextant altitude of the moon (Ms) to Ma. Parallax and refraction of the moon seems to be the largest area of intermediate discrepancy, I may need to examine my formulas in that area and follow the flow of Bruce's tables again to find other differences. All in all, I am happy to be in the ball park. It is extraordinary how sensitive this technique is to very small differences in measurement or method of reduction.
Clear skies in Boston, I will try to get a series of observations today to share with the group.
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