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    Re: USCG Student Sample Problem #4
    From: Antoine Couëtte
    Date: 2013 Apr 28, 04:05 -0700


    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

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