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    Re: Graphically solving haversine calculation
    From: Jaap vd Heide
    Date: 2015 Nov 14, 01:18 -0800

    Örjan,

    Timing of sunrise/sunset at high latitudes is the other side of the same issue. Not the same, but very much related. (you might observe azimuth + LHA = 180° at sunrise/sunset)

    I have put them both in one figure for the day of (or very near to) summer solstice (dec = 23.4N) at your latitude. (see the attachment) From the diagram you can tell that the haversine of the zenith distance - and the altitude of the sun with that - doesn't change to fast with "cranking the LHA-clock-hand" in the inner circle.

    For winter solstice, the left hand side diagram will be mirrored in the central vertical axis, leaving very little daylight left. In the right hand diagram, declination at the top will be to the right (equals to the South) and the azimuth at sunrise becomes 180° minus the azimuth at sunrise at summer solstice. LHA sunrise at winter solstice will be 180° minus the LHA (with respect to LAN) at summer solstice.



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