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    Re: GHA = GAST - RA Astronomical Almanac vs Nautical Almanac
    From: Stan K
    Date: 2014 Mar 22, 20:36 -0400
    Mike (and members),

    Ignore my message of seconds ago.  I typed before I read :-[.


    -----Original Message-----
    From: Mike Mayer <mwmayer{at}tds.net>
    To: slk1000 <slk1000---.com>
    Sent: Sat, Mar 22, 2014 3:32 pm
    Subject: [NavList] GHA = GAST - RA Astronomical Almanac vs Nautical Almanac

    Anyone know what I'm missing? In comparing the Sun's GAST - RA from the Astronomical Almanac to the GHA in the Nautical Almanac there are cases that seem to be too far off. For example, for January 1, 2014 at 0 UT I get:
    GAST = 6h42m17.0580s = 6.704738333h (Page B13)
    RA = 18h45m35.31s = 18.759808333h (Page C6)
    GAST - RA = -12.055070000 = 11.944930000h = 179.17395° = 179°10'26.22"
    = 179°10.437'
    The Nautical Almanac has 179°10.2'
    The difference is 0.237', which is outside the accuracy the Nautical Almanac specifies for the GHA Sun data in the paragraph numbered 24 on page 261 of the commercial version of the Nautical Almanac 2014.
    What am I missing ?
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