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Re: S-tables: where to have a look at them?
From: Stan K
Date: 2017 Mar 17, 18:31 -0400
From: Stan K
Date: 2017 Mar 17, 18:31 -0400
Tony,
Here are a couple of paragraphs from the Celestial Tools Help regarding the S-Table:
Two versions of the S-Table are provided: the original (the default), by Mike Pepperday, which was included in the Nautical Almanac for a few years in
the early '90s, and is still available as a booklet; and a modified version, by Rodger E. Farley, available in his book "Celestial Navigation in a Teacup"
(formerly "The Armchair Celestial Navigator"). Both versions are derivatives of H.O. 211, and, as such, also have a "forbidden zone" where K is
between 82° and 98°, which is handled in the same manner as in H.O. 211 . The worksheeet for the Pepperday version as shown in the Nautical
Almanac and the booklet is very similar to the H.O. 211 worksheet. (Pepperday revised it to an improved version after the publication of the booklet,
but it was never published.) The Farley version uses an original worksheet. In both cases Celestial Tools uses a worksheet similar to that of H.O. 211,
but with the nomenclature changed to agree with the particular version being used.
The Farley version uses + for N and W, and - for S and E. It also uses an unconventional definition of LHA, similar to meridian angle t. For example, if
LHA is 350°, it will be shown as -10°. The Farley version also does not mention the interpolation requirement where the value of the derived parameter
K is near 90° (as in H.O. 211), but there is an implication in the example in the book that "eyeball interpolation" should always be done for any
parameter. (The Pepperday version specifically says not to bother using anything but the nearest tabulated value except in the case of K near 90°.)
Celestial Tools, however, is programmed so that interpolation is only done when the K value is from 82° to 98°.
The booklet of Pepperday's version is available from Celestaire for $9.95. Farley's "Celestial Navigation in a Teacup" is available for free at www.teacupnavigation.net/Celestial_Navigation_in_a_Teacup_v.pdf
The rest of Rodger's web site is worth looking at, as is his free "Teacup Celestial" computer program.Stan
-----Original Message-----
From: Tony Oz <NoReply_TonyOz@navlist.net>
To: slk1000 <slk1000@aol.com>
Sent: Fri, Mar 17, 2017 6:00 pm
Subject: [NavList] S-tables: where to have a look at them?
From: Tony Oz <NoReply_TonyOz@navlist.net>
To: slk1000 <slk1000@aol.com>
Sent: Fri, Mar 17, 2017 6:00 pm
Subject: [NavList] S-tables: where to have a look at them?
