Simrad AUTOPILOT SYSTEM AP50 - Manual (Page 180)

Simrad AP50 Autopilot
178
20221032B
Heading – The horizontal direction in which a ship actually
points or heads at any instant, expressed in angular units from a
reference direction, usually from 000° at the reference direction
clockwise through 359°.
IMO MSC(64)67 – (International Maritime Organization)
Performance standards for heading control system.
ISO 11674:2000(E) – (International Organization for
Standardization) Specifies the structure, performance, inspection
and testing of heading control systems.
Loran C - A complex radio navigation network developed by
the US coast guard, to assist a navigator in determining his
precise location. The acronym, Loran C, stands for Long Range
Navigation. It is an all weather 24 hour a day electronic system
of shore based radio transmitters.
Magnetic bearing – Bearing relative to magnetic north;
compass bearing corrected for deviation.
Magnetic deviation – Compass error; the difference between
the reading of a compass and the actual magnetic course or
bearing due to errors in the compass reading.
Magnetic heading – heading relative to magnetic north.
Magnetic variation - A magnetic compass points to the
magnetic north pole. The difference between this direction and
true north is the magnetic variation. The amount and direction of
this variation is dependent upon where on the earth you are
located.
NMEA 0183 - A format (language) designed to permit
communication between various types of marine electronic
equipment. In essence, this is a two-wire shielded, serial data
link, permitting one device to talk while other devices listen.
Numerous different sentences are available, permitting
communication between various different devices.
Relative wind – The speed and relative direction from which
the wind appears to blow with reference to a moving point (also
called apparent wind).
Rhumb line – A line that passes through all meridians at the
same angle. When drawn on a Mercator chart, the rhumb line is
a straight line. However, the Mercator chart is a distortion of a
round globe on a flat surface, so the rhumb line will be a longer
course than a great circle route.
Route - A stored sequence of waypoints. These waypoints will
be listed in the order in which you desire to follow them.