I don't know how everyone is deriving their bearing angles...but if you are doing it crudely, like I am, with a portable receiver & a hand compass, you have to adjust for magnetic declination to get the true "map north" bearing. In my case, here in SW PA, the magnetic declination is 9 deg W. 9 deg can make a BIG difference over a distance. Declination varies widely with location; it's easy to find yours online. Whether you add or subtract the declination from your compass reading depends on where you are. This is a very signif potential source of error in our readings. And I can never remember whether to add or subtract it; have to figure it out each time!
Fred Schroyer Freelance Science Writer / Editorial Consultant 955 Sixth Street - Waynesburg, PA 15370 (40 air mis S of Pittsburgh - 20 air mis N of Morgantown, WV) Home 724-627-8844 - Work 304-599-7830 x 1120 [EMAIL PROTECTED] _______________________________________________ IRCA mailing list [email protected] http://montreal.kotalampi.com/mailman/listinfo/irca Opinions expressed in messages on this mailing list are those of the original contributors and do not necessarily reflect the opinion of the IRCA, its editors, publishing staff, or officers For more information: http://www.ircaonline.org To Post a message: [email protected]
