NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: digital compass, etc
From: Stephen Ellis
Date: 2000 Sep 12, 8:49 AM
From: Stephen Ellis
Date: 2000 Sep 12, 8:49 AM
). Patrick McVey wrote: >>sensitivity varies due to large pieces of). The >>sensitivity varies due to large pieces of...^metal in your vessel^( >This is swung by turning the boat slowly thru 360 degrees. I also have a >autohelm 3000 autopilot this is swung in a similar manner. >Except that in the autohelm it is necessary to then point the boat on a >fixed bearing and remove any offset in the deviation. Thanks for the help. I don't have a boat. I should have said that I installed my digital compass in my CAR. Thanks Patrick, and Aubrey. When I calibrated my compass, I had to drive around in a circle two times, stop, then two more times. Sounds like they do that in boats too, except in the autohelm you have to take that extra step. I didn't know that, I never heard of the Autohelm. Stephen Ellis -----Original Message----- From Aubrey O'CallaghanTo: NAVIGATION-L@LISTSERV.WEBKAHUNA.COM Date: Monday, September 11, 2000 6:20 PM Subject: Re: digital compass, etc >I've got a Furuno electronic compass on my boat (connected to the radar). >This is swung by turning the boat slowly thru 360 degrees. I also have a >autohelm 3000 autopilot this is swung in a similar manner. >Except that in the autohelm it is necessary to then point the boat on a >fixed bearing and remove any offset in the deviation. >This is not necessary with the Furuno compass. How can the Furuno "know" >any offset ? > >Aubrey. > >At 08:39 AM 07-09-00 -0700, Patrick McVey wrote: >>I don't mind though slightly off subject. You're doing what's called, >>"swinging the compass." The sensor (fluxgate I believe) and microprocessor >>are testing the sensitivity of all 360 degrees and making a correction >>table for each point of the compass (probably all 360 points). The >>sensitivity varies due to large pieces of