Simrad ES80 Reference Manual page 268

Simrad ES80 Reference Manual
Description
Trawl sensor systems (such as Simrad PI, PX and ITI) communicate headrope depth,
and/or the distance from the headrope to the footrope (trawl opening), to the ES80 at
regular intervals. The information can be used to draw the upper and/or lower trawl
lines in the ES80 echogram. If another trawl or catch monitoring system is used, and
this system does not provide the trawl opening and/or trawl distance automatically, the
values must be entered manually.
This information is required for the trawl echogram to be generated. Without the depth
of the headrope, the echogram would appear like a standard pelagic echogram controlled
by the and settings.
Range Start Range
Note
The Trawl echogram is only drawn when trawl position information is available.
The distance from the headrope to the footrope (trawl opening) can be manually set on
the page. This is useful for trawl sensor systems that do not measure the trawl
Trawl
opening, or when the measured distance is unreliable. You can also provide the distance
from the vessel to the trawl opening. The depth of the headrope must however be
imported from the catch monitoring system. The page is located in the
Trawl Installation
dialog box.
The biomass calculations in a Trawl echogram are not restricted by the bottom detection.
This means that the bottom echo will be included in the calculations if it appears within
the chosen range.
Tip
For closer investigation, you can use the Zoom information pane to enlarge
echoes from the water column.
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