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A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Lunars question for Frank
From: Bill B
Date: 2005 Sep 21, 00:13 -0500
From: Bill B
Date: 2005 Sep 21, 00:13 -0500
> On Sep 12, 2005, at 3:46 PM, Bill wrote: > >>> Bill has offered some code to do the job, but perhaps Mike wishes to >>> understand the problem and how to solve it, rather than paste in >>> another's >>> code. >>> >>> My first word of advice, to Mike and to many other listmembers, is to >>> acquire a copy of "Astronomical Algorithms", by Jean Meeus. >> >> George >> >> Thanks for the thorough coverage, and the correct spelling of Meeus. >> My >> spreadsheet did not attempt to deal with Sun or moon angular >> separation from >> bodies. I tended to use the moon and Franks lunars to determine >> sun/moon, >> moon/star distances. Not yet good enough to do Sun/star shots ;-) >> >> Therefore, your latest posting was of great interest to me, and starts >> to >> give me a handle on dealing with the Sun and moon separation angles. >> Thanks >> again. >> >> I did send along some of the background used in constructing the >> spreadsheet >> to Mike et al, which included Meeus formulas, as well as text captures >> of >> postings by you and Frank some time back on the subject including >> formulas. >> As you have pointed out, there are several ways to skin that cat, and >> my >> spreadsheet addresses only one of them. >> >> Bill Frank When using your lunars calculator, it reports not only error in the sextant reading (error in lunar), but angular distance off in degrees and minutes to the tenth (error in longitude). Has the angular distance off in longitude been adjusted by the program for latitude, therefore should be translated directly into nautical miles by converting to decimal degrees and multiplying by 60, or should an adjustment be made for latitude when determining nautical miles off? I understand it appears to be a silly question, a degree is a degree, but if it can knock 24% off my error in nautical miles, worth a shot ;-) Thanks Bill