NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Matus Tejiscak
Date: 2021 Oct 9, 13:53 -0700
Dear Ed,
others already gave a lot of very useful advice. What I haven't seen mentioned yet is that I observe a different IE when looking at the reflected image of the Sun than when looking through the index glass at a star. The difference is about +13' for the Sun vs. about +20' for the stars. I'd recommend to measure the IE through the index glass as well.
My method is to take a sequence of sights from a tripod and calculate the St Hilaire intercept for each sight from my known position, which amounts to direct IE measurement. Then I use statistics to determine the IE from this collection of IE samples. That's where things get tricky, as I seem to get a multimodal distribution of errors -- even when adjusting the angle in only one direction to eliminate the difference in backlash -- so I'm still in the process of figuring out what else could affect this.
Matus
