NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Sextant experiment
From: Peter Monta
Date: 2021 Jul 27, 20:46 +0000
From: Peter Monta
Date: 2021 Jul 27, 20:46 +0000
Have you any idea why the error is so large while your individual measurments are in range +-0,1 minute of arc.
The only thing I can think of is a bias between the two contact types. Since my micrometer is always increasing, for the first contact the suns are approaching and about to touch, and for the second they are overlapped and about to separate. Perhaps there's really a 0.15' gap when I think they are touching (or some other arrangement of error between the two). That would bias the first contact 0.15' low and the second 0.15' high.
The individual measurements do have internal scatter of 0.3' peak-to-peak; I don't think they're reliable to +-0.1' (maybe twice that under these ideal conditions). But there probably is a problem with my technique (or, less likely, some wear on the arc at this often-used position of 0 degrees).
Cheers,
Peter
