NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Basics of computing sunrise/sunset
From: Marcel Tschudin
Date: 2009 Jun 19, 15:35 +0300
If my memory does not disappoint me, I hopefully remember correctly the following findings in a PhD thesis from sometime at the beginning of the last century. The person was measuring in Davos (which is within the mountains) at various times of the day the brightness density at different places in the sky. His findings were - if I hopefully remember right - that after the theoretical sunset, not the one at the mountains, the brightness density started to drop on all places in the sky at the same rate. A measurement of this drop made in the zenith would therefore be representative for all other parts in the sky.
Marcel
BTW: This PhD thesis was not one in Astronomy, Physics or Meteorology; it was one in Mathematics ...
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From: Marcel Tschudin
Date: 2009 Jun 19, 15:35 +0300
Frank, you wrote:
The same calculation is used for inland locations as for locations with a sea horizon. What does it mean when the standardized calculated time of sunrise is 08:30, e.g., if you're living in a mountain valley?
If my memory does not disappoint me, I hopefully remember correctly the following findings in a PhD thesis from sometime at the beginning of the last century. The person was measuring in Davos (which is within the mountains) at various times of the day the brightness density at different places in the sky. His findings were - if I hopefully remember right - that after the theoretical sunset, not the one at the mountains, the brightness density started to drop on all places in the sky at the same rate. A measurement of this drop made in the zenith would therefore be representative for all other parts in the sky.
Marcel
BTW: This PhD thesis was not one in Astronomy, Physics or Meteorology; it was one in Mathematics ...
--~--~---------~--~----~------------~-------~--~----~
Navigation List archive: www.fer3.com/arc
To post, email NavList@fer3.com
To , email NavList-@fer3.com
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