B&G Zeus 12 - Manual (Page 57)

56
Navigation Parameters
Navigation method
Different methods are available for calculating the distance and
bearing between any two points on a chart.
The great-circle route is the shortest path between two points.
However, if you are to travel along such a route, it would be
difficult to steer manually as the heading would constantly be
changing (except in the case of due north, south, or along the
equator).
Rhumb lines are tracks of constant bearing. It is possible to
travel between two locations using Rhumb line computation, but
the distance would usually be greater than if Great circle is used.
Steering alarm limits
Arrival radius
Sets an invisible radius around the destination waypoint.
When the arrival alarm is activated, an alarm will appear when the
vessel is within this radius.
Off course limit
This parameter defines the vessel’s accepted offset distance from the
leg. If the vessel goes beyond this limit an alarm will be activated.
Off course alarm must be enabled/disabled in the alarm panel.
Magnetic variation
Converts magnetic North data to true North.
Auto automatically converts magnetic north to true north. When using manual mode,
you will have to input the local magnetic variance.
Datum
Most paper charts are based on the WGS84 datum, Zeus also uses WGS84.
If your paper charts are based on a different datum you can change the setting in the
Zeus system to match your paper charts.
Coordinate system
Controls the format of lat/lon coordinates displayed on the panels.
Phantom Loran
Enables phantom loran, for waypoint entry, vessel and cursor position display.
Loran settings
Allows setting of GRI and preferred TD pairs for vessel and cursor position display.
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