NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Perihelion today, greatest SD
From: Marcel Tschudin
Date: 2013 Jan 2, 20:48 +0200
From: Marcel Tschudin
Date: 2013 Jan 2, 20:48 +0200
Frank, you asked:
Can you measure a change in the Sun's SD of only 0.3 minutes of arc?
Yes, in photos. With the camera settings I used for my measurements the sun diameter changed during the year between about 103 and 107 pixels. With the known calibration of the camera one actually can calculate how many pixels the diameter should be in the photo. To certain extend this allows then correcting the limb positions in photos where the exposure is not optimal.
Happy New Year to all NavList members!
Marcel
Happy New Year to all NavList members!
Marcel
