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    Re: Lunars Calculator
    From: Frank Reed
    Date: 2008 Jul 01, 15:47 -0400

    Dave W, you wrote:
    "Many of us have found Frank's "Lunars Calculator" an incredibly useful
    resource.  Perhaps it's its format that makes it so helpful and easy to
    use."
    
    Then just to remind everybody that this calculator has an ancestor, both in
    function and format, I am attaching to this message a spreadsheet which was
    prepared back in 2002 by Arthur Pearson. Arthur was a lunarian hobbyist just
    about the time I joined the group but he has since moved on to other things.
    I will also attach his pdf description of lunars, which is very nice but a
    bit out-dated, to a later message.
    
    And you wrote:
    "Nonetheless, some comments.  There is a pull down menu that hints at
    offering an Apparent Time option as other of his programs have.  Lately,
    I've been working through some examples from Moore, and this would have been
    helpful.  (Possible to get eq of time from Frank's other programs by asking
    for sun's 0hr GHA for both GAT, and GMT.)"
    
    Yes, good point. I always intended to add that functionality for my own
    analyses but I ended up using the calculator more indirectly since when you
    find old lunar observations in logbooks there is always some ambiguity about
    just which definition of time they're using. When a navigator says "12
    August, shot a lunar at 2:35pm" does he mean by sea account, with a day that
    starts at noon, or is it a civil day, which starts at midnight, or even an
    astronomical day, which starts at noon like a sea day but a different date?
    And did he just read the time off his watch which may have been set by a
    time sight six hours earlier (when they were in a different longitude) or
    has he calculated the best estimate of local time based on the vessel's
    changing position? But it would be nice if the software also calculated the
    local time from the altitude, when possible.
    
    "Also, sometimes it would be nice to have lunar distance input between
    centers in addition to near or far options.  (likewise input altitudes
    center vs upper or lower)"
    
    This could get confusing, especially for beginners, but there might be a way
    to set up some hidden "advanced" options.
    
    "I would use an option, if there was one, to include input data on the same
    page with the output calculated results.  (Useful for printouts while
    "working things out".)"
    
    Yes. Definitely.
    
    "Would be nice to give true and apparent altitude of moon and body on the
    results page.  (Would reduce my add versus subtract errors.)"
    
    Yes.
    
    "Thanks again for the Calculator!"
    
    You're welcome. I have added some of these features to the stand-alone
    software which is just about ready. I think I will mostly leave the web
    version as it is.
    
     -FER
    
    
    
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    File: 105618.aplunarsupload.xls
       
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