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    Re: GHA of the Moon
    From: Peter Hakel
    Date: 2020 Oct 3, 22:01 -0700

    Frank wrote:
    You added:
"But the moon has been my biggest problem.  Yesterday I did find a neat excel program from Navigation Spreadsheets that may solve my moon problem"
    Yes, I was going to suggest that as an option for you. The developer is a NavList regular (Peter? You here?), and I'm sure he can help you with any questions you may have on those spreadsheets.

    Hello Jim,

    Since you want to write your own programs in, say, Python or Java, I will suggest an alternative to using the actual Navigation Spreadsheets.

    Before I wrote those almanac spreadsheets back in 2009, I decided to test my understanding of the formulae from Jean Meeus’s book by coding them in Fortran first. I attached that code to this message as the file named almanac.zip. Assuming that you have a gfortran compiler installed on your computer, unzip the file, open a terminal, execute the following commands in the almanac directory:


    and enter UT according to the prompt. You should get the same outputs as given by those Excel spreadsheets. (This is just a suggestion; you may prefer other ways of compiling and running such programs.)

    Then you’ll want to edit the source file named main.f90 starting at line 45 where you’d replace manual UT entry with something automated by a loop in order to print a Moon table according to your needs.

    Peter Hakel

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