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    Star to Star Distance Sextant Calibration
    From: Michael Bradley
    Date: 2019 Apr 10, 14:59 -0700

    A crude new toy, automating by spreadsheet, in a limited way, a calibration check on a sextant using star to star distances, is in the attached file.

    I searched the web for a while, couldn't find anything of the like.

    The planner section of the spreadsheet gives distances accurate enough to pre-set the sextant and so ease the sight taking process.

    The calculator section does the precision work, but needs the green data boxes filling. Please note that it is set up assuming the work is done 'all north'. If a south declination star is chosen, you'll have to change the sign of its decimal declination yourself. Ditto EPLat. I never said the spreadsheet was sophisticated....

    Thanks to Frank Reed for 'Easy Lunars', from which parts needed for the calculator section were lifted.

    Thanks to Bill Ritchie - I've been using Astron for the almanac data, calculated altitudes, and refraction values to put into the spreadsheet.

    The Winter Hexagon is in a prime position after sunset right now, at least for we northerners.

    It's seems sensible to use 'sideways' distances for large arcs, say more than 45 degrees. Lunar type sight technique is needed for that,

    but is not terribly dificult to do if the planning preset is used.

    No warranty offered or implied. Please use, modify, crit, suggest improvements etc as you might wish.

    Michael Bradley

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