Two On A Big Ocean The Story of the First Circumnavigation
of the Pacific Basin
in a Small Sailing Ship


      

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Re: Latitude and Longitude by "Noon Sun"

From: Henry C. Halboth (no email)
Date: Tue Jun 07 2005 - 09:28:49 EDT

  • Next message: George Huxtable: "Re: Corrections for speed and bearing"

    I have just a little difficulty with the terminology "noon sights vs LOP
    sights", since the end result of the noon sight is an LOP, albeit a
    special case calculation. It is possibly also worthy of note that, as
    most newly made "navigators" graphically plot when using the intercept
    method, there are inadvertent errors introduced that have not been
    discussed on this list. In the days before plotting sheets, which
    incorporate certain distortions in printing, LOP intersections were
    calculated - even in my day. You just didn't louse up "expensive" charts
    by repetitious plotting. Just a little historical aside - not a
    criticism! Further, the intercept method was generally not employed in
    hydrographical surveying, i.e., in super-accuracte position determination
    by astronomical observation.

                                                                   Henry

    On Mon, 6 Jun 2005 22:59:29 EDT Frank Reed <> writes:
    > Lu Abel you wrote:
    > "I don't see noon sights vs LOP sights as an either-or proposition
    > -- at
    > least not for a "good" navigator (which I hope all on this list
    > would
    > claim they either are or aspire to). "
    >
    > A good navigator is the guy who pulls a functioning spare GPS
    > receiver out
    > of a metal box after your vessel has been struck by lightning and
    > all the
    > other electronics are fried! <g>
    >
    > -FER
    > 42.0N 87.7W, or 41.4N 72.1W.
    > www.HistoricalAtlas.com/lunars
    >


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