NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Antoine Couëtte
Date: 2013 Apr 28, 04:05 -0700
http://fer3.com/arc/m2.aspx/USCG-Student-Sample-Problem-4-Rudzinski-apr-2013-g23714
Hello Greg,
Thanks for mentioning the SUN parallax which I had totally forgotten.
I then have computed the SUN Height correction again from my 1983 copy of the US NA (still the same Height Corrections Tables in use to day ?) :
Starting from your published Hs = 28°20'7, and with IE = +2.0' I get :
Sextant height corrected for Index Error = 28°22.7'
Dip correction from US NA (HOE = 100 ft) -9.7'
Sextant height corrected for IE and DIP = 28°13.0'
Refraction Correction from US NA = -1.8' (you used -1.9')
SD (LL to Center) correction = +16.1'
Topocentric Center Height (Hct) = 28°27.3'
SUN Parallax Correction 8.8" cos Hct = +0.1'
SUN Observed Geocentric Height Ho = 28°27'4 (you found Ho = 28°27'2)
SUN DR Geocentric Hc = 28°47'2 (same value as yours)
Therefore the 0.2' difference between our both intercepts now becomes fully accounted.
Best Regards
Kermit
----------------------------------------------------------------
NavList message boards and member settings: www.fer3.com/NavList
Members may optionally receive posts by email.
To cancel email delivery, send a message to NoMail[at]fer3.com
----------------------------------------------------------------