NorthStar MX500 Operator's & Installation Manual page 259

Glossary
COMPASS HEADING
COMPASS MAGNETIC VARIATION
COURSE
COURSE LINE
COURSE OVER GROUND
CROSS TRACK ERROR (XTE)
CURSOR
DATUM
Version 3.0
Compass reading before correction for deviation and variation.
See MAGNETIC VARIATION.
The horizontal direction in which a vessel is steered or intended to
be steered, expressed as angular distance from north clockwise
through 360°. (Strictly the term applies to direction through the
water, not the direction intended to be made good over the ground).
The course is often designated as true, magnetic, or compass as
the reference direction is true, magnetic, or compass, respectively.
A line, as drawn on a chart, extending in the direction of a course
(Rhumb Line).
Course made good relative to the sea bed.
The perpendicular distance from the vessel to the actual course
line (track) as defined in the active route.
A flashing rectangle superimposed on a character position in the
display window, indicating that a character may be entered in that
position, or that the existing character may be changed via the
keyboard.
The framework on which the coordinates used to define position
on the Earth's surface are based. In the navigator, a datum is de-
fined by the following parameters:
A and I/F. Size and shape of a reference ellipsoid.
DX, DY, DZ. Position of the reference ellipsoid origin in relation to
the satellite datum ellipsoid origin.
Operator's Manual
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