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A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: GPS & Magnetic Bearings
From: Brooke Clarke
Date: 2003 Feb 9, 17:32 -0800
From: Brooke Clarke
Date: 2003 Feb 9, 17:32 -0800
Hi Robert: Yes, every 5 years you can load the new magnetic data. No, it requires returning the unit to a franchised dealer who updates the firmware for a charge. Robert Eno wrote: > So are you saying that you GPS has the capability to acquire updated > magnetic deviation data? Is this done using a computer disk? > > Robert > ----- Original Message ----- > From: Brooke Clarke> To: > Sent: Sunday, February 09, 2003 6:11 PM > Subject: Re: GPS & Magnetic Bearings > > > Hi Robert: > > > > You're very close. The World Magnetic Model is based on empirical > observation, not a theory. The model uses a 12th order > > polynomial based on past observations. My Motorola GPS uses flash memory > and can be updated for a fee. The model is much more > > complex than just the variation (I misused deviation in the prior post), > it has magnitudes for all three vectors North-South, > > East-West and the largest one Up-Down. > > > > Have Fun, > > > > Brooke