Kongsberg Simrad ST90, Reference Manual

Page: 484 / 690

482
442704/A
AGC (Automatic Gain Control) function
The
AGC
(Automatic Gain Control) function runs an automatic analysis of the echo
strength. Based on this analysis the ST90 system maintains a proper dynamic range based
on all the current echo values. This is done by automatically reducing the gain if you have
reverberation and noise, or increasing the gain if the acoustical conditions permit it.
How to open
You open this function from the
Active
menu.
Description
The AGC (Automatic Gain Control) function adjusts the gain using an image processing
algorithm.
This processing depends on the strength of the echo signal. The image is analysed to
identify reverberation and echoes. Based on the analysis the weak echoes are amplified,
while the strong echoes are weakened. The result is a "normalizing" effect that reduces
noise and reverberation.
The automatic gain control is functional up to the maximum range of the ST90 system.
You can choose from four different AGC settings. The settings define the difference between
the maximum and minimum echo level for the automatic gain control to take effect.
The chosen AGC (Automatic Gain Control) setting is only be applied to the currently active
view. Activate the relevant view
before you select the AGC setting.
Simrad ST90 Reference Manual