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## A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding

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Re: Celestial Navigation In The Gps Age: Typos?
From: Stan K
Date: 2017 Aug 31, 14:53 -0400
Tony,

Yes, definitely typos, which were not in the first or second printing.  They are only in the expanded material of the third printing.  I hope John is still reading NavList.  He should be made aware of these.

As far as the sun altitude corrections go, they consist of refraction , parallax, and semi-diameter.  refraction and parallax are essentially the same for lower and upper limbs, but semi-diameter goes from limb to center by adding for a lower limb sight, but subtracting for an upper limb sight.  Using some nice round numbers for refraction, parallax, and semi-diameter, in that order:

Lower limb:  -1' + 0.1' +16' = +15.1'
Upper limb:  -1' + 0.1' -16' = -16.9'

Stan

-----Original Message-----
To: slk1000 <slk1000@aol.com>
Sent: Thu, 31 Aug 2017 13:24
Subject: [NavList] Celestial Navigation In The Gps Age: Typos?

Hello.
I'm reading the "CELESTIAL NAVIGATION IN THE GPS AGE" by John H. Karl (the ePub version).
I've noticed several definitely typos there:
(Chapter 7, Polaris with only a Sextant):
• text right under the formula 7.1b is Lat = HO- 41' cos(-13') = HO- 40'; there should be Lat = HO- 41' cos(-13°) = HO- 40'
(Chapter 7, Position without St.Hilaire):
• formula 7.5a has sin dS instead of the proper sin d2
• formula 7.5c has sin HS instead of the proper sin H2
Also I wonder why the Chapter 10, Accuracy advises to use the different corrections for the lower and upper limbs of the Sun (the -13.5' and +18.5' respectively). Yes, their sum is the very familiar 32' of the Sun's diameter, but why they are different?
Regards,
Tony
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