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A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Ho 208 question
From: Stan K
Date: 2014 Feb 24, 16:15 -0500
From: Stan K
Date: 2014 Feb 24, 16:15 -0500
A little help here. I only have a few pages of H.O. 208 to work with (provided by Gary - without him I would have nothing to work with), so I'm beginning to suspect that this problem is related to the similar situation in H.O. 211, where there is no table value for an LHA of zero, since the log of zero is undefined. Am I on the right track?
Well, maybe not. I just made a change that seems to deal with the LHA = 0 condition better, getting answers more consistent with the other sight reduction methods. The pages I have indicate there is a column for every degree of LHA from 1 to 360 (equivalent to an LHA of 0), but I have no way of knowing whether my calculated values are correct.
Stan
Well, maybe not. I just made a change that seems to deal with the LHA = 0 condition better, getting answers more consistent with the other sight reduction methods. The pages I have indicate there is a column for every degree of LHA from 1 to 360 (equivalent to an LHA of 0), but I have no way of knowing whether my calculated values are correct.
Stan
-----Original Message-----
From: Randall Morrow <randall.f.morrow@kp.org>
To: slk1000 <slk1000@aol.com>
Sent: Mon, Feb 24, 2014 11:12 am
Subject: [NavList] Ho 208 question
From: Randall Morrow <randall.f.morrow@kp.org>
To: slk1000 <slk1000@aol.com>
Sent: Mon, Feb 24, 2014 11:12 am
Subject: [NavList] Ho 208 question
The results have improved for my use of Ho 208 but an ususual case is giveing me trouble.
With a GHA of 478* 49.8 and assumed Lon of 118* 49.8 the LHA is 360 or zero.
My circa 1940 .pdf does not have a zero LHA column. If I use 360*60.0' the results are way off. Plugging my sight data into the Ho 208 calculator called "Celestial Tools" I got an intercept of over 1000 miles.
With a GHA of 478* 49.8 and assumed Lon of 118* 49.8 the LHA is 360 or zero.
My circa 1940 .pdf does not have a zero LHA column. If I use 360*60.0' the results are way off. Plugging my sight data into the Ho 208 calculator called "Celestial Tools" I got an intercept of over 1000 miles.
Sight data:
Sirius
Date 22 Feb
Time 20-29-06 PDT
ZD +8
Hs 37*57.5 (Already corrected for AH use)
SHA 258* 33.21
GHA Aries 212* 58.5
Ref. -1.3
IC -0.4
USNO reduction shows Hc 37*56.1 and intercept of 0.3
Sirius
Date 22 Feb
Time 20-29-06 PDT
ZD +8
Hs 37*57.5 (Already corrected for AH use)
SHA 258* 33.21
GHA Aries 212* 58.5
Ref. -1.3
IC -0.4
USNO reduction shows Hc 37*56.1 and intercept of 0.3
As a post script, does anyone have a .pdf version of Ho 208 that has the extra column headings at the top and bottom for 90-180, 180-270 etc.?
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