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    Re: Longitude by Sunset
    From: Marcel Tschudin
    Date: 2012 May 8, 00:15 +0300
    {at} hac.vanasten:

    I think to slowly be able to "see" the combined effect of parallax and refraction which you indicate. I made before the mistake of imagining the observer being at rest and the moon moving, but it is of coarse the other way round. I imagine now a model situation where the moon is for an observer first in the zenith. Here both, parallax and refraction are zero. Now the topocentric observer starts to rotate relative to the moon which is assumed to stay at a fixed position. By rotating the earth with the observer on top of it both, parallax and refraction start to increase with different signs. This appears indeed to lead to a conflict when the observer reaches a position where the moon is close to his horizon. It looks to me like the resulting effect could be shown with a numerical simulation on a simple geometrical model.

    Marcel
       
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