NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Magnetic Declination etc.
From: Doug Royer
Date: 2004 Feb 12, 15:41 -0800
From: Doug Royer
Date: 2004 Feb 12, 15:41 -0800
Frank
stated:
Bear in mind that there are SEVERAL competing, similar terms like "declination" and "variation" for the difference between true north and magnetic north. It's always best to say what you mean when you write about this material, and there's no point being too pedantic about which one is "right".That's true and a good point.Grid referance projections(mil,topo etc.)use declination.I believe all terrestrial maps are like this.G>M M>G conversion aid for grid projections.grid to magnetic(major less than general;subtract declination)magnetic to grid(general greater than major;add declination)Marine charts(mercator,gnoumatic,lambert etc) use variation.GETVMDC conversion aid for charts.Gyro,Error,True,Variation,Magnetic,Deviation,Compass
