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    Re: Sun semidiameter
    From: Bill B
    Date: 2007 Apr 15, 17:06 -0400

    > From: "Frank Reed" 
    > Of course, if you really want to drive yourself nuts with the
    > variation of the Sun's semi-diameter, go to the table for the Sun's
    > total altitude correction on the inside front cover of the Nautical
    > Almanac. Suppose the Sun's observed altitude was 10d 00'. Suppose the
    > date is March 31st locally, but April 1st in Greenwich. So what's the
    > altitude correction? According to the table, interpreted very
    > literally (!), the correction is 11.0 minutes of arc if it's March 31,
    > but it's 10.7 minutes if the date is April 1. Take your pick.
    It's not difficult to interpolate for a UL and LL values near the break
    point, so one can derive quarterly values, useful for artificial horizons or
    beach shots perhaps.  On the water in a small craft I really don't worry
    about it.
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