Kongsberg Simrad ST90, Reference Manual

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Size Distribution information pane description
The Size Distribution information pane presents a histogram with the echoes from single
fish. The calculations are based on the fact that different fish species have different echo
strength. The histogram presents the actual size of the fish by weight, length or echo
strength (shown in dB).
How to open
Before you open an information pane, you must first click in an Inspection view to make it
"active". The information provided will only be valid for the selected view.
To open the information pane, click in the chosen view to activate it, then select
Size
Distribution
on the top bar. To close the information pane, select it one more time on the top
bar. You can also select
Close
in the top right corner of the pane.
Note
Information panes are only available for Inspection views.
Description
The Size Distribution information pane presents a
histogram with the echoes from single fish. Only
the fish detected by the sonar beam in the
Inspection
view are used to create the histogram.
The displayed number shows the average size of
all the fish in the histogram. The value is presented
in the unit you have chosen on the
Size Distribution
page. For an accurate reading of the X-axis, place
the cursor on the axis, and read the value from the
tooltip label.
Note
The measurement accuracy in the Size Distribution
information pane depends on the vertical angle of the
inspection beam. A beam that points nearly straight
down corresponds to a traditional echo sounder. This gives the best accuracy since the fish
is then viewed from above. If you use a smaller beam angle, you may see the fish from the
front or back. This gives significantly smaller echoes, and thus low measurement accuracy.
The abbreviation
TS
is commonly used for target strength. The
target strength
is a measure
of the area of an object detected by a sonar or an echo sounder. The target strength is usually
Simrad ST90 Reference Manual