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    Re: SpaceX Starlink launch: photo celestial
    From: Frank Reed
    Date: 2020 Jan 14, 12:01 -0800

    Dave Pike, you wrote:
    "So how far away was the camera?"

    Two miles. Right where it should be. :)

    The width of that big rocket hangar (SMARF/SPOC) across the line of sight is around 310 feet. We can determine its angular width in the photo since there are many star pairs nearby in the high-resolution image. That turns out to be just about 99 minutes of arc. As always:
      (m.o.a) / 3438 = (size across line of sight) / distance,
    so we can solve for distance. I get 2.04 (statute) miles. With 5% error bars, let's call it 1.94 to 2.14 miles. Now I can draw an error ellipse based on the astronomical azimuth and the distance off from the SMARF/SPOC building, Happily my original position estimate is safely inside the ellipse.

    And yes, I know: this is over-kill in a silly game. :) I left this part out  from my last post because I assumed we were at a point where no one was interested anymore.

    Frank Reed

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