NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: astrocompass still in use
From: JC Sutherland
Date: 2002 Sep 27, 22:27 +0100
From: JC Sutherland
Date: 2002 Sep 27, 22:27 +0100
Quoting Robert Eno: > Interesting application. > > How on earth did you manage to keep your astrocompass perfectly level > whilst > it was mounted on your boat? > > Robert > > > Hi. Yes, levelling is a problem but as it happened it was quite a calm day and we were in an enclosed harbour. Each mesurement was done several times (under engine with no sails up) and I chose the best steadiest moment for each observation. A particular difficulty was that on a couple of headings the sun was obscured by the mast. These readings were extrapolated from the others and I had to recheck them next day. It was satisfying that they came out as expected. Another useful trick was to calculate the magnetic co-efficients from the data (the program is quite simple) and then to synthesize the deviation curve from these. This results in a smooth curve to best fit the data. > > > Clive Sutherland. > > Wantage, (where King Alfred burnt the cakes). > > 51deg 38.2 min N 001deg 24.5min W