Kongsberg Simrad ST90, Reference Manual

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442704/A
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.
6 Open the button and select
Apply to all
if you wish to use the chosen setting in all the
views in the current presentation mode.
Related topics
Getting started, page 34
Starting normal operation, page 52
Gain function, page 422
Changing the vertical angle of the sonar beams
In order to detect fish or schools in the water column you may need to change the angle of
the sonar beams. The transmitted sonar beams can be tilted electronically.
Context
The current tilt is shown with a solid line in the Vertical view. In the Horizontal view, the
current settings for range, gain and tilt are shown in the top left corner of the view.
With 0° tilt the sonar beam is transmitted in parallel with the sea surface. With +60 degrees
tilt the beam is directed towards the bottom.
The challenge is to find a tilt that prevents the fish echoes to be "buried" in reverberation
and bottom echoes.
• If you use a high tilt value (A) the fish are easily disguised by bottom echoes. A strong
RCG (Reverberation Controlled Gain) setting will remove the bottom echoes. As the
distance from the bottom to the fish increases, the fish echoes become clearer. However,
this assumes that the fish echoes are considerably stronger than the bottom echoes.
Simrad ST90 Reference Manual