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    Re: Correcting for the movement of an observer: a plausible explanation?
    From: David Pike
    Date: 2019 Dec 23, 07:20 -0800

    Frank you said:  If you're flying in a supersonic aircraft, you can make MOO and MOB cancel out. The stars will stand still.

    You don’t quite need to be supersonic.  Going west over the North Atlantic at about M0.84 or 480kts TAS at FL430 and around 57N will do it.  We occasionally found ourselves using the same values out of Vol 3 most of the way across.  This got interesting if celestial was all you had left, and you just happened to catch a partial eclipse of the Sun as happened to us on 26th February 1979, because it seemed to follow us for rather a long time.  I found I could still shoot the Sun, but I did begin to feel things were starting to stack up against us.  I suppose the other possible disadvantage with a periscopic pendulous reference sextant was that the stars must have moved past twice as fast on the way home although I can’t say I ever noticed it.  DaveP


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