NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Norman Baatz
Date: 2025 Apr 27, 04:50 -0700
The simple arc correction factor is doing pretty good for me. See the new image, produced from all sightings with the Davis Mark 3, a total of 52 (13x4) up to today, since I started using the procedure I described. 6 morning lines (those with positive slope), 7 afternoon (negative slope).
So far, so good: almost all LOPs pass through the 2 NM circle around the actual location. Nice, but for sure using a plastic sextant to get these results is a pain (checking / correcting errors for all 52 sightings).
The visible "right-shift" *looks* like a chronometer error of, say, -4s, but actually all timings should be correct to within one second. I'm also starting to see a non-linear effect, in that lower altitudes seem to need a lower correction factor, so maybe a "true" arc correction table will still emerge. But I can already see that this will then cause the "right shift" to be even more pronounced, for which I currently have no explanation.
Norman
