Kongsberg Simrad ST90, Reference Manual

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• If you use a very small tilt (C) you are not bothered by bottom echoes. However, if the
sea surface is gusty you will see echoes from the waves. These echoes are normally
rather weak, and they hardly move in relation to your vessel.
• By means of a medium tilt angle (B) you are able to pick up scattered fish or schools if
these are located at some distance above the bottom. The upper school in the illustration
appears on the sonar picture before the bottom echo, while the lower school will easily
be disguised by the bottom echoes. Once again you can activate the RCG function to
improve the reading.
Tip
With the various beams provided by the ST90 system, it may be difficult to understand the
concepts. How do these beams "behave" in the water? By means of a graphic presentation,
the
Beam Visualization
dialog box attempts to give you a better understanding of how the
acoustic beams are transmitted into the water. Open the
Beam Visualization
dialog box
from the
Setup
menu.
Procedure
1 In a Vertical view, click on the tilt line, keep the mouse button depressed, and drag
the line up or down.
Optionally:
2 Click in any view to make it active.
The active view is identified with a thicker border. Unless you use the
Apply to all
function, all changes you make will only be applied to this view.
3 Observe the
Main
menu.
Its default location is on the right side of the display presentation.
4 Select
Tilt
.
5 Make the necessary adjustment.
The following methods can be used to adjust this setting:
a Select [ + ] or [ - ] to choose the requested setting.
b Place the cursor on the button. Press and hold the left mouse button. Move the
cursor horizontally over the button. Release the mouse button when requested
value is shown.
c Select the middle of the button to open it. If you have a keyboard connected to the
ST90 system, type the requested value.
Getting started