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Re: Lunar altitudes
From: Jan Kalivoda
Date: 2003 Apr 14, 11:53 +0200
From: Jan Kalivoda
Date: 2003 Apr 14, 11:53 +0200
One remark more: The method of lunar altitudes for finding the GMT seems ideal to me for the observation above an artificial horizon (ashore, of course). The problems with dip, with the blurred sea horizon, with the short period of twighlight would then disappear completely. With an artificial horizon one can wait through the whole night, until the Moon with a star (not very distant from the Moon, but their azimuths don't matter too much in this case) come to the prime vertical. Many occasions can arise through the month and one could expect better results than with lunar distances, isn't it? . This could be very important in early days, when the knowledge of the accurate longitude was an exception outside the Europe and USA (maybe Caribbean) and the method of combining local time and longitude to obtain the GMT was therefore unavailable in remote countries. Had you anybody heard anything about such usage? I didn't. Maybe somebody from the list, who is in possession of a sextant and an artificial horizon, can try this method? It cannot be too difficult, I guess (from the desktop). Jan Kalivoda ----- Original Message ----- From: "George Huxtable"To: Sent: Sunday, April 13, 2003 10:19 PM Subject: Re: Lunar altitudes