Seismic Amplifier Gain gainType extGainType refinedGainType refinedExtGainType POSC 1.0 automatic gain control The gain of each channel is controlled automatically and independently of other channels. instantaneous floating point The gain is determined for each sample based on the amplitude of that channel without prejudice by earlier samples or the amplitude of other channels. binary Gain is allowed to vary only by factors of two, but the time at which the changes occur are recorded so that the gain effects can be removed by processing. quaternary The gain is allowed to vary only by factors of four. ganged automatic The gain of all channels is the same although automatically determined, the basis being one single channel or the average energy level of a number of channels. programmed The gain as a function of recorded time is programmed and preset prior to recording. fixed The gain is arbitrarily set to a fixed value prior to recording.