NorthStar MX500 Operator's & Installation Manual page 275

Glossary
VELOCITY MADE GOOD (VMG)
VHF
VISIBLE SATELLITE
VMG
VTS
WAYPOINT
WAYPOINT CLOSURE VELOCITY (WCV)
WAYPOINT PASS CRITERIA
WCV
Version 3.0
The speed by which the vessel is moving in the upwind direction.
When tacking, the optimization should be based on VMG (assum-
ing that TWD is expected to be fairly constant). See also
WAYPOINT CLOSURE VELOCITY.
Very High Frequency – A set of frequencies in the MHz region.
A satellite whose orbit has placed it above the earth's horizon (el-
evation angle >0°) from the location of the navigator and is, there-
fore, available for acquisition. The navigator will not use satellites
with an elevation angle < 5°.
See VELOCITY MADE GOOD.
Vessel Traffic Service
A point, usually along the track of the vessel or vehicle, whose
position coordinates may be stored in the navigator. The point
position is the basis for the heading, range, heading-to-steer, esti-
mated time of arrival, and steering display calculations.
The speed the vessel is moving in the direction of the next waypoint.
WCV should be used for optimization in cases where TWD is ex-
pected to vary drastically before the waypoint is reached. See also
VELOCITY MADE GOOD.
The criterion by which the navigator determines the passing of a
waypoint. The criterion is selected in CFG 1, Navigation.
See WAYPOINT CLOSURE VELOCITY.
Operator's Manual
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