A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Marcel Tschudin
Date: 2012 May 31, 00:55 +0300
There are three ways to determine the fixed angle:
1. Observe and time the reflected Sun is on the horizon directly without using a camera.
2. Observe the same with the camera for better results because the setting image can be zoomed. No pixels get counted in this procedure.
3. Observe with the Sun off the horizon then subtract the angular value determined from the pixel count to get the reflector fixed angle.
Note that there is no calculating of refraction for the lower reflected images because the light is not traveling through the atmosphere at that lower altitude but at the true higher altitude so there is no Ref(Alt1) only Ref(Alt1 + Alt2). Don't forget that the light is traveling back and forth between two pieces of glass on the reflector just as mirrors on a sextant