A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Greg Rudzinski
Date: 2017 Oct 30, 15:32 -0700
Work and average 10 sunlines from a known position and unknown height of eye using zero for the dip value. The average intercept will be a reasonable approximation of the dip. Another more precise method would be to go to the sea level point and take an obsevation of the elevated observation point using an artificial horizon. Divide the observed angle by 2 and do basic right triangle trig using the distance between the two points as picked off a chart or worked out with GPS positions. Also note the GPS elevation as given at sea level then again at the observation point. The difference should be close to your height of eye.