NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: My first observations with natural horizon
From: Alexandre Eremenko
Date: 2005 Aug 6, 15:53 -0500
From: Alexandre Eremenko
Date: 2005 Aug 6, 15:53 -0500
On Sat, 6 Aug 2005, Bill wrote: > Nice results. I would be interested in seeing details, > especially if you > reduced each shot after averaging. Here is a nice series (the best one). August 4, wind 12 knots, boat speed 6-7 knots, small waves, good horizon. Observation while sitting on a cockpit bench, estimated height 160 sm, dip= -2.3', IC=.6' GPS: 54d05.6'N, 8d02.7E GMT 6:34:16 sext alt 22d27.9 error -0.1' GPS: 54d04.7'N, 8d05.0E GMT 6:45:27 sext alt 24d06.4' error -0.1' GPS: 54d04.5'N, 8d05.8'E GMT 6:50:24 sext alt 24d51.2' error +0.1' The dip estimate is crucial here. I noticed that my eye was on the same height as the second wire of the railing, and then measured the height of this wire over water level with a rope. But as the boat was moving up and down on the waves, this height changed substantially. It is strange that my observations from the shore (a beach in Helgoland), under almost ideal conditions, were less precise than my best observations from the boat. Alex.
