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The basic fluxgate compass is a
simple
electromagnetic device that employs two or more small coils of wire
around a core of highly permeable magnetic material, to directly sense
the direction of the horizontal component of the
earth's
magnetic field. The advantages of this mechanism over a
magnetic compass are that the reading is in electronic form and can
be digitised and transmitted easily, displayed remotely, and used by an
electronic
autopilot for course correction.
To avoid inaccuracies created by the
vertical component of the field, the fluxgate array must be kept as flat
as possible by mounting it on
gimbals
or using a
fluid suspension system. All the same,
inertial
errors are inevitable when the vessel is turning sharply or being tossed
about by rough seas. To ensure directional readings that are adequately
stable, marine fluxgate compasses always incorporate either fluid or
electronic
damping.
An alternative is to use a 3-axis fluxgate
magnetometer to provide a 3D flux vector, and the magnetic heading
is derived from the flux on a plane
perpendicular to gravity, thus providing immunity from pitching, and
rolling.
More
Fluxgate Compass Data and Information
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