There was thread on electronic compasses who knows more about this
devices
a friend of mine is looking for an compass accurate enough for his auto
pilot on his ship
at the moment his compass is heavily influenced by gsm telephone and
other sources
I looked on the web there are gps and electronic compasses or combined
with nmea 0183 output
or ssi and rs232 .
The ship is 600 ton's cargo carrier 40 meters long moving trough small
european canals .
I think the system at the ship is still analog and the shipper has to
correct all the time as on
open water .
What sensors are available with great accuracy.

Marcel
Amsterdam
Email : M.v.d.Bilt@fibre.A2000.nl