Northrop Grumman Sperry Marine VisionMaster FT, User Manual

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Radar/Chart Radar User Guide Charts
65900010 12-39
Shallow and Deep Contours
The Deep Contour and Shallow Contour areas are highlighted on the Video
circle by colour shading, with the shallow water areas indicated by lighter
shades. Contours, prohibited areas, and areas with special conditions are
considered dangerous if their depth is less than own ship’s safety depth or
no depth is defined for that object.
WARNING!
THE CHART SHADING BASED ON THE DEFINED CONTOURS
MAY NOT ALWAYS BE ACCURATE DUE TO THE GEOMETRY OF
THE DEPTH CONTOURS IN THE AREA, AS WELL AS
LIMITATIONS IN THE SYSTEM CHART DATA AT ANY GIVEN TIME.
THESE LIMITATIONS MAY INCLUDE NON-AVAILABILITY OF
USER-SPECIFIED DEPTH CONTOURS, VARIANCES BETWEEN
DATA CONTENT ON OVERLAPPING CHARTS, AND OTHER DATA
ISSUES. THE OPERATOR MUST TAKE THESE FACTORS INTO
ACCOUNT AND USE ALL AVAILABLE SOURCES OF
INFORMATION REGARDING DEPTH, AS APPROPRIATE TO THE
NAVIGATION AREA.
For an illustration of deep and shallow contour areas on a chart display,
refer to the Detail tab in Chart Legend sub menu.
The default value for shallow contour is 2 metres
(maximum value = Safety Depth).
The default value for deep contour is 30 metres
(minimum value = Safety Depth).
When own ship's safety depth is changed the deep/shallow contour colours
may change although the contour outlines will remain on the video circle.
Changing Chart Depth/Height Values
To change the default values click in the required field and move the
trackball left to decrease the value or right to increase. Click the left key
again to set the value.
The contour and depth values set for the selected chart are also shown in
the Detail tab in Chart Legend sub menu.