NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Greg Rudzinski
Date: 2013 Apr 27, 16:34 -0700
Antoine,
For the Sun observation in problem #4 a reduction by both USNO and NA/Pub 229 has been done. The USNO has GHA at 169* 4.7' vs. 169* 4.8' NA. Declinations match. USNO Hc is 28* 47.1' vs 28* 47.2' Pub 229/NA. The parallax of +0.1' was not applied in either case. These small discrepancies may be contributing to our differences.
G
Re: USCG Student Sample Problem #4
From: Antoine Couëtte
Date: 2013 Apr 27, 12:15 -0700
RE : http://fer3.com/arc/m2.aspx/USCG-Student-Sample-Problem-4-Rudzinski-apr-2013-g23703
Hello Greg,
You wrote :
QUOTE
My guess on the Sun difference of 0.2' would be the way rounding of semi diameter is done between your program and USNO.
UNQUOTE
I would surprised that USNO would make such a 0.2' rounding on the SUN Semi-Diameter which is very well known and changes very slowly. On my side, I do not round the SUN SD and do not use any Irradiation factor either. For this example I am using SD = 16'117 (same value as the 16'1 you have published).
How about getting third party results ?
Peter, Andrés or Yves (or others) ?
From : Nov 01 st, 2013 at UT 22:59:53 / N 26° / E 143°55'3 , with HOE = + 100 ft , standard conditions and Sextant Height (already corrected for Instrument Error) equal to 28°22'7 for SUN LL,
what intercept do you find ?
Thanks for your Kind Attention and Best Regards
Kermit
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