NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Celestial Tools V4.7.0 Beta1
From: Stan K
Date: 2014 Nov 27, 23:19 -0500
From: Stan K
Date: 2014 Nov 27, 23:19 -0500
Celestial Tools has a new enhancement, and I would appreciate any help List members could provide in testing it.
As we have discussed in the past, as explained in paragraph 24 on page 261 of the Nautical Almanac, the hourly GHA values for the Sun on the daily pages are "fudged" by adjusting them by up to 0.15' to reduce the error due to ignoring the v-correction. Previous versions of Celestial Tools provided a fairly accurate value of the GHA of the Sun, in agreement with most, if not all, similar computer programs, but these values were often not in agreement with the Nautical Almanac. Since the purpose of Celestial Tools is to help students find their mistakes in doing "manual" sight reductions, this discrepancy always bothered me, but I think I have it worked out.
In the Sight Reduction tool, there are now two options available when the Sun is selected. The default is "NA val. of hourly GHA", which is the enhancement. It is hoped that it will accurately duplicate the Sun's hourly GHA as presented on the daily pages of the Nautical Almanac. The other option is "Accurate val. of hourly GHA", which produces the same results as previous (recent) versions.
In the Noon Sight tool, the "accurate" value of the Sun's hourly GHA has been replaced with the "Nautical Almanac" value. This also is new and needs testing.
The Help file has not yet been updated, since more testing is required.
Attached is the first beta of V4.7.0. Thanks in advance for your help.
(For those who have not used Celestial Tools before - Font size should be set to 96 dpi (called small, smaller, standard, normal, or 100% depending on operating system). However, for the purposed of checking the GHA values, this is not necessary. It just won't be pretty.)
Stan
