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    Re: Sextant Accuracy and anomalous dip.
    From: Gary Harkins
    Date: 2003 Mar 17, 20:37 EST
    In a message dated 3/17/2003 8:09:43 PM Eastern Standard Time, ffive{at}TPG.COM.AU writes:

    Is your house at sea level?  If not you will have error caused by your
    >elevation.
    Is this identical to the dip factor caused by height of eye?
    > Usually these can be ignored at moderate elevations, but in your
    >case, attempting to get ultimate accuracy, they may be a factor.  The
    >error will be greater when the sight is a smaller Hs.
    Why?


    No.

    Imagine yourself on top of a mountain taking a sight.  Imagine that the sight measures 45 degrees using a bubble horizon or artificial horizon.  At sea level and the same geographic location (if that were possible) the sight would measure higher.  If you measured the same 45 degrees at sea level you would have to be further away from the sun's GP.  I hope that's clear, it's easier to show using a sketch.

    Gary Harkins C400 #140 "Cygnus"
    Website   http://www.hometown.aol.com/htycgary/myhomepage/index.html
    Harbour Towne Marina, Muskegon, Michigan Slip C-28
    Harbour Towne Yacht Club, Life Member
    C400 National Association
    United States Power Squadrons-JN

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