NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: sunrise observation.
From: Marcel Tschudin
Date: 2013 Feb 17, 14:57 +0200
From: Marcel Tschudin
Date: 2013 Feb 17, 14:57 +0200
This is an other observation which appears to support the previously mentioned finding that the visibility of the first/last sun ray is about 2.5 min of arc after/before the appearence/disappearence of the sun's limb at the (sea) horizon.
Using for the sight reduction Henning Umland's calculator one obtains for an apparent altitude of 0 ' an intercept of -5.8 nm and for 2.5 ' altitude an intercept of -2.7 nm.
Marcel
Using for the sight reduction Henning Umland's calculator one obtains for an apparent altitude of 0 ' an intercept of -5.8 nm and for 2.5 ' altitude an intercept of -2.7 nm.
Marcel
On Sun, Feb 17, 2013 at 11:54 AM, Örjan Sandström <pokerbacken@yahoo.com> wrote:
This morning I observed the sunrise above the ice (ht of eye 1m), sadly I caught upper limb only I was fighting a fish when lower rose.
That upper limb rose at 07:26:17 according to my watch (currently about 3.2 seconds out but that was accounted for)
temp was -11°C
1016mbar
DR N 64°43' E 021°14'
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