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    Re: LAN sight help !!
    From: Millard Kirk
    Date: 1999 Aug 14, 17:16 EDT

    Hi Barry,
    I'm trying to learn Celestial Nav on my own and I have a question
    regarding LAN sights...I understand the concept, the math and the
    conversion of ARC time.BUT for instance:
          mer pass + DR-LON(W) = GMT of LAN
           12h 06m + 8h 09m 12s = 20h 15m 12s
      How does 20h 15m 12s help me in predicting LAN at my long....Is it
    that simple that I just don't see it..???
    Looks as if you have the right answer but, can't see it.   Just subtract 8h
    from 20h 15m 12s and you have your LAN.
    Back calculating from 8h 09m 12s time at DR-LON(W)  your LON is 122d 02min
    18sec.  From your mer pass data I know that the sun will pass over
    Longitudes of 0, 15, 30, 45, 60, 75, 90, 105, 120, .... 180 at 12:06 Zone
    Time.  If you were at 120d exactly then the sun would pass over you at 12h
    06m, but you are 2d 18sec W of 120d therefore it will take the sun a little
    longer to get directly overhead of  you.  The sun travels 1 degree in 4
    minutes.  So you are 2d 18s = 2.3d West of 120.
       2.3d X 4 m/d = 9.2m or 9m 12s.
    You just add the 6m from the mer pass to 9m 12s and you get 15m 12s after
    12:00 or LAN = 12h 15m 12s.
    Or am I missing something???
    Learning the Hard Way!!
    Millard Kirk KB8YQO       | mailto:mkirk@XXX.XXX
    116 Lewis Ave                    | http://webpages.marshall.edu/~mkirk/
    Barboursville, WV               | A West Virginia Blue Water Sailor
    25504                                 | Phone: (304) 736-6544
                                               | First United Methodist Church,
    Barboursville, WV
                                               | Homepage

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