A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: David C
Date: 2020 Apr 11, 17:14 -0700
Recentlt there was a thread about IE vs IC which I did not follow. Maybe I should have done. I wanted to confirm the sign convention used by the anti-spoof app so I set my phone and tablet side by side. The index error is 4' on the arc which means I have to subtract 4' from sights. I therefore set IC to -4' but it added 4' to the sight. I changed IC to +4' and the number was subtracted.
My interpretation is that IE = +4' and IC = -4' but the app thinks otherwise.
It is fortunate that I have two devices to compare (-;