At 05:59 -0400 21/9/01, Doggre@xxxxxxx wrote:
To a mariner, the U.S. Navy & Coast Guard, and I think aviators (help me out
here, Chris) "deviation" is compass error, caused by nearby magnetic metals
(like the hull of a ship) which is corrected (mostly) with the compensating
magnets inside the compass housing. Tough to get all "deviation" out of a
compass.
Yes, I now use a compass that has deviation after 20 years of using
inertial navigation systems with no deviation. But the deviation is
so small compared with the size of the graduation of the compass card
that it is barely worth mentioning - not to mention my inability to
hold a heading within 2 or 3 degrees anyway.
A chart showing the deviation of a compass at various headings (determined by
"swinging ship") is posted alongside the compass binnacle.
The horizontal variation in the earth's magnetic field from True geographic
north is termed "Variation".
Rich (no more OT from me this week, promise)
Nor me.... honest.
OM content: I have not yet tried a method of mounting the little
camera in the little aircraft. I had better engender confidence of
my students in their instructor first!
Chris
P.S. What's a "map"?
Chart is a navigator's (backseater in a fast jet) term and therefore
below the front seater's dignity to mention ;-).
--
<|_:-)_|>
C M I Barker
Cambridgeshire, England.
+44 (0)7092 251126
mailto:imagopus@xxxxxxxxxxxxxxxx
... a nascent photo library.
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