
NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Stan K
Date: 2014 Jun 5, 21:39 -0400
I sent him the following message:
On 31 May 2014 02:20, <slk1000@aol.com> wrote:
Mike,
I am the author of Celestial Tools, a computer program I wrote for the United States Power Squadrons (USPS) to help students with their work. (Latest beta available at www.celestialtools.webs.com.) One of the tools, SR Methods, includes the Law of Cosines, NASR, 249, 229, 214, 211, 208, etc., though only the Law of Cosines and NASR are currently taught by USPS. The others were added for the sake of people on NavList, an online community of traditional navigation enthusiasts, who still enjoy reducing sights by older methods. Someone on NavList suggested I add your S Table, which I was familiar with, having a 1991 Yachtsman's Edition Nautical Almanac. Apparently your S Table has a larger following than I thought, and is being sold by Amazon, Celestaire, and others. So I started thinking about it and found something I felt was unusual. Where other Ageton-type methods use a nice round multiplier of a factor of 10, your table seems to use a number that I cannot begin to guess where it came from. If analyzed correctly,
S(x) = 94.2934*log10[cosecant(x)] (thanks to Rodger Farley of Teacup Navigation).
I realize that the multiplier can be anything that would make the logs easier to work with, but 94.2934 is making my head spin. If it is not some kind of trade secret, please let me know how it was selected.
Thanks.
Stan Klein
I got a very nice response from Mike Pepperday. In a million years I would never have figured why he selected the multiplier he did.
-----Original Message-----
To: slk1000 <slk1000@aol.com>
Sent: Sat, May 31, 2014 6:30 pm
Subject: Re: S Table question
BTW, the "single page" S-Table is on its way. If there is any interest, I'll see what I can do about making copies.
Stan