NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Norman Baatz
Date: 2025 Apr 21, 01:07 -0700
After not restricting my search to the Davis Mark 3, I found previous messages where people have been using Frank's GPS Anti Spoof app to calibrate their sextant:
NavList: "GPS Anti Spoof" app for Sextant Calibration (Dustin Baenen)
NavList: Re: Sextant calibration by observations (Modris Fersters)
Nice results—and lots of work
My calibration process is still ongoing, and as I have written elsewhere, currently dividing all measured angles by 1.002 is doing a pretty good job for me, especially when I take four sightings each in the morning, around noon, and in the afternoon, graphing them, having my spreadsheet calculate a line through them, and randomly picking one sighting each that is not an outlier. I'm getting fixes that are less than 2nm away from the actual location with my Davis Mark 3, using an artificial horizon. I must say, I did not expect to get this from this plastic sextant.
Norman
