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A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Old style lunar
From: Ken Muldrew
Date: 2004 Dec 9, 16:36 -0700
From: Ken Muldrew
Date: 2004 Dec 9, 16:36 -0700
On 9 Dec 2004 at 17:41, Alexandre Eremenko wrote: > But the standard deviation of longitude is 0.3 deg, > that is 20' which probably better describes his accuracy Don't forget that his lunar position depends on a time-sight measurement as well as the lunar distance. His watch was often out by more than 10 minutes each day, and the direction of error was unpredictable, so he was entirely dependent on the time sight. Any error there would propagate into the lunar error. > But this is probably easy to check. If anyone has a 1800 > (or around) almanach. Just compare it with Frank's online > lunar dist predictor. As I understand it gives accurate results > for the XIX century. Bruce Stark was kind enough to send me some pages from the 1800 almanac this past summer. Perhaps I can check a few entries to see what Thompson was up against. Ken Muldrew.
