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    Re: Latitude by Noon Sun for Beginners
    From: Henry Halboth
    Date: 2009 Apr 28, 17:28 -0700
    I have no idea as to how the problem is worded, however, are you sure it's not supposed to be worked as an ex-meridian sight, which would give the Latitude for the time of sight, which in turn would have ro be advanced to noon,
    Just a quick thought based on the info you have given.

    --- On Tue, 4/28/09, JKP@obec.com <JKP@obec.com> wrote:

    From: JKP@obec.com <JKP@obec.com>
    Subject: [NavList 8089] Latitude by Noon Sun for Beginners
    To: NavList@fer3.com
    Date: Tuesday, April 28, 2009, 11:49 AM

    I've been following with great interest, if with less than complete comprehension, the recent threads on finding position at and around noon.

    I'd like to divert a tiny new rivulet from that stream-- a back-to-basics thread on noon sights for latitude. I don't like those titles for how-to books that end in "...for Dummies," so I'm using the kinder term "...for Beginners."

    I've been working the latest Nav Problem in Ocean Navigator magazine, and I'm finding I can't get the latitude the editor does from the noon sight data presented.  My main stumbling block seems to be that the time given for the shot is not the time I consider Local Apparent Noon for the DR longitude used.  Wouldn't that be essential?  If the sun is observed at 12 minutes or more after LAN, how does one account for that difference? 

    My main source of instruction is Dutton's (12th edition), which I find usually gives excellent and thorough explanations of procedures.  The article on latitude by noon sun focuses on how to determine LAN and what to do with the Ho obtained then.  I've found nothing so far about accounting for a time difference and the fact that the sun is not at its zenith when observed before or after LAN.  Much is made of combining the vessel's change of position east or west with that of the sun to pinpoint LAN, but the magazine problem provides no data about course or speed.

    I'll bet one you can tell me somnething that will make me slap my forehead and exclaim "Of course!"  Fire away!

    Thanks in advance,
    John P.

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