Reducing Noise And Reverberation With The Agc (Automatic Gain Control) Function - Kongsberg Simrad CS90 Reference Manual

Operating procedures
Note that , (Time Varied Gain) and are not filters, but included
Gain TVG Display Gain
only to illustrate the complete "signal path".
Related topics
Operating procedures, page 76
Improving the recognition of fish and schools using receiver filters, page 112

Reducing noise and reverberation with the AGC (Automatic Gain Control) function,

page 113
Reducing propeller noise and interference with the Noise Filter, page 115
Reducing bottom and surface reverberation with the RCG (Reverberation Controlled
Gain) function, page 116
Reducing noise and false echoes with the Ping-Ping Filter, page 117
Reducing the strong bottom echo to see fish close to the seabed, page 118
Adjusting the intensity of the echo presentations, page 119
Reducing noise and reverberation with the AGC (Automatic
Gain Control) function
Identifying echoes from fish and schools can often be challenging when they are hidden
by noise and reverberation. When sonar conditions are poor, effective tuning of the
filters in the CS90 system may be necessary to achieve a satisfactory result. Automatic
Gain Control (AGC) is one of the tools provided to remove noise and reverberation
from the echo presentation.
Context
The (Automatic Gain Control) function runs an automatic analysis of the echo
AGC
strength. Based on this analysis the CS90 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.
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