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    Re: Computer generated Almanac
    From: Dan Allen
    Date: 2003 Sep 5, 08:54 -0700

    On Friday, September 5, 2003, at 06:36 AM, Vic Fraenckel wrote:
    > Loath as SOME users of this list are to introducing computers into
    > celestial
    > navigation, I would like to find someone that has used the "JPL
    > Planetary
    > and Lunar Ephemerides" data to actually produce a computer almanac. I
    > would
    > like to do so but am not sure how to proceed. I am NOT interested in
    > getting
    > the data via the many excellent Web based systems as accessing the web
    > is
    > NOT practical while at sea.
    > Any enlightenment will be appreciated.
    I got that CD-ROM years ago and found it hard to figure out how to use
    it.  The data files on the CD-ROM are huge and are of the highest
    accuracy.  Source code for a FORTRAN program is on the CD and other
    people have since made C versions, but I am still at a loss as to how
    to use it all.  I confess I have spent little time on the project, but
    it is not very user friendly.
    The simplest way of producing a computer almanac is to code up the
    algorithms given in Jean Meeus' "Astronomical Algorithms" book.  I have
    done this for the sun in the Awk programming language and it is found
    on my web site at:
    Awk is a very plain and simple language in the spirit of the C
    programming language, and this one page of code could easily be
    translated into C, Perl, Python, Java, or whatever.  You are free to
    use it as a basis for your own almanac.

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