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Re: Longitude from moon culmination
From: Lars Bergman
Date: 2023 Dec 16, 06:29 -0800
From: Lars Bergman
Date: 2023 Dec 16, 06:29 -0800
Further to my previous post I believe that the calculated moon's GHA has to be reduced back to the bright limb before it becomes equal to westerly longitude. This is due to the fact that it was the bright limb that you timed passing the meridian. I have designed an example using the 2011 Nautical Almanac only, and a log table. As I didn't found a suitable star for my example, I invented one with a matching SHA. And I have used the simple SHA reduction from limb to centre that Robin Stuart described (I thought it had to be much more complex ...). The result in my example seems to be too good to be true, my "designed" longitude was 18°E. Until someone corrects me, I believe it is just a random good luck with the numbers.
Lars
