Re: astrocompass still in use
Subject: Re: astrocompass still in use
jcs@XXX.XXX
Date: Fri Sep 27 2002 - 17:27:02 EDT
Quoting Robert Eno <enoid@XXX.XXX>:
> 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
