98
922-00027001/2.2
This filter is most useful for midwater trawling where there is usually no strong bottom
appearing.
Related topics
TVG Correction filter
Clicking this button will enable or disable the TVG Correction filter. This filter reduces
TVG-amplified noise at further ranges where no targets appear.
You can adjust the filter percentage (applied to the range) in the
Display Widget
.
This filter will remove the range-dependent TVG effect on incoming echo data
starting from the range percentage that you define up to the maximum range.
For example, if your current rage is 0.5 m to 10 m, then a TVG Correction of 80 percent
will apply the filter to the sonar view beyond the 8 m range rings. The TVG value that
was increasing with range will be replaced with a constant value (equal to the TVG value
at the given range).
The TVG Correction range will appear as an overlay in the sonar view (using your preferred
units of distance).
Related topics
Adjusting the TVG (Time Variable Gain) setting, page 53
Show/hide Grid
Turns the display grid on or off.
In the up and down sounder views, the grid lines are a series of evenly spaced
horizontal lines in the window. In the net opening view, circular range rings
indicate the distance from the Sonar Head to the relevant target(s).
Each line in the sonar view is labelled to show the distance between the lines. The scale
is set automatically.
Tip
You can change the units of measurement in the
Preferences
dialog box.
Simrad FM90 Reference Manual
Summary of Contents for FM90
Page 2: ......
Page 140: ... 2018 Kongsberg Maritime ...