BTW, even Polaris isn't a perfect indicator of true north. It's up to 2 degrees off for latitudes from the equator to 60 degrees north, and you can read the nearby constellations to see when it's right on. Consult Bowditch if you really care.
73,doug
From: Bruce Bostwick lihan161051@sbcglobal.net Date: Sat, 9 Jan 2010 13:52:01 -0600
On Jan 9, 2010, at 1:47 PM, Dave Guimont wrote:
At 11:37 AM 1/9/2010, you wrote:
Randy, True North is used as a reference. Magnetic North changes with observer location and time.
Art, what does mag north have to do with time??
Magnetic deviation changes slowly over time as the earth's magnetic field changes. The rate and current deviation are usually pretty precisely known for most areas.
"No nation was ever so virtuous as each believes itself, and none was ever so wicked as each believes the other." -- Bertrand Russell
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