Geopsy: Automatic gain control

Automatic Gain Control pop-up window

Automatic gain control (AGC), reached from the Waveform menu, modifies the amplitude of the signals in the active signal viewer to retrieve signals with a constant RMS value. By clicking on AGC, a pop-up window appears asking for the window width. This is the moving window length, in seconds, on which the average RMS value around the current point is computed. The amplitude of the current point is divided by this RMS value. The default window length is 0.1 s.

This option is useful for instance for reflection seismic to increase the amplitudes of attenuating signals. It is not advised for array processing techniques aiming at deriving the phase velocities of surface waves : Ambient vibration array, Active source experiment (MASW)

Automatic gain control (AGC) creates new temporary signals in the active viewer.

See also: Automatic Gain Control (Wikipedia)