Northrop Grumman Sperry Marine VisionMaster FT, Руководство пользователя

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Radar/Chart Radar User Guide Charts
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In some circumstances it may be desirable for the operator to select a zero
value for Look-Ahead time or distance, for example, when ownship is in a
crowded harbour area. If a zero value is selected a `
Minimal Safety
Region' caution is generated. The caution is removed from the Alerts list if
the time is increased to at least 1 minute, or the distance to at least 0.3 NM.
Safety region alerts in the Dangers window are suppressed when
zero Look-Ahead time/distance is selected.
As the safety checking is done periodically there is a delay of a few
minutes for dangers in the dangers list to time out after the look
ahead range has been adjusted. This prevents the same dangers
from being added or removed from the list, and re-alarming due to
fluctuations in the ship's course.
Added Breadth enables a safety region width to be added to either side of
own ship’s beam. The value defines the safety breadth from ship's beam in
metres that the system checks for dangerous objects (for example,
underwater obstructions) that are shallower than the Shallow Contour
specified in Chart Depths/Heights.
If no added breath is defined (i.e. the value is set at
0 )
then safety checking is to the beam of the ship. Unlike
Look Ahead range no caution is generated when
added breadth is at
0 .
2. To change the value click in the Added Breadth field and move
the trackball left or right. As the safety breadth is changed the width
of the safety region either side of the ship’s beam changes
accordingly.
3. The default setting for the generation of Caution alerts is off. To
display alarms for cautions tick the Alarm On Cautions check box.
4. To display the safety region tick the Show Safety Region check
box. If the Look-Ahead value or added breadth is changed, the
length and width of the safety region adjust accordingly. As own
ship moves across the screen, the line is redrawn every 30
seconds.
When there is a difference between the COG
and the Heading the safety region will display a
dog legged rectangle, this being the calculated
safety region taking into account the different
COG and HDG values. If the COG and HDG
bearings are the same the safety region
rectangle is drawn as straight lines.