Doc. P/N:
WSP-009-008
Version: V1.3
Issue Date:
April 2014
16
3.4
Fish Options
The Fish Options window contains preferences for watercolumn target detection. The user is able to
select any depth range and threshold for target detections, and view a detection histogram with an
adjustable 30 minute history. The settings contained in this window affect both the 2D and 3D fish
shown on the charting displays (NB: the 2D fish will ignore the history setting).
3.4.1 Fish Display Options
►
Between Depths
: The user can set a depth range for watercolumn
detections. The WASSP program will ignore detections outside of
this range.
►
From Seafloor
: If the user is only interested in near-bottom targets,
the
From Seafloor
option will only use detections that are located
a certain distance above the seafloor, ignoring the rest of the water
column. If Bottom Lock is enabled (see “Bottom Lock” on page
12), the Single / Triple Beam display will show a green line where
the detections start.
►
From Range
: If the user has set detections to “All Targets in Ping”
(see “System” on page 46), then the “From Seafloor” setting
becomes “From Range”. In this case, users are generally working in
deep water without a discernable seafloor. The detection range will
be from the last signal acquired up the water column. The depth of
the last signal will depend on the setting of the range dial.
3.4.2 Fish Threshold
Generally speaking, large fish return a stronger signal than small fish. The Fish Threshold control
dial allows you to tune the “Fish Detection” for your vessel. The control has a range of 1 to 30. It is
recommended that this threshold is set high enough that only the desired targets are ‘detected’. This
control also affects the fish shown on the charting displays as well as the Fish Histogram.
3.4.3 Fish Histogram
The histogram shows a gain-adjusted colour table to help reference the Fish Threshold to normalised
signals on the Sonar and Single / Triple Beam displays. The Fish Threshold setting is visible as a white
line on the colour table. By adjusting the Fish Threshold and referring to the histogram, you will find
an optimum level for your vessel’s installation.
