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    Re: A lesson in a photo
    From: David Pike
    Date: 2016 Aug 28, 13:15 -0700

    I saw that effect a couple of times from TIKI on a flat calm sunny day in the Baltic summer.  I just assumed it was the wake of a ship that had travelled for miles or the Baltic equivalent of the Loch Ness Monster.
    Parachute diameter = 115ft = 18mm on my print
    Capsule = 18mm above horizon on my print = 115ft
    Ripple = 1mm on my print.
      Lets assume it's
    half a minute of arc
    Angle of capsule above horizon = 18 x ½ = 9’ = 0.15

    Tan0.15 = Perp/Base = 115/Range in ft.
    So Range = 115/tan0.15 x 5280 = 8.3 statute miles. The SpaceX Dragon website says about ten miles.  Maybe I’ll stop looking for that magic equation.  DaveP

       
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