The AMP_DISTRIBUTION port outputs a distribution of the normalized amplitudes across the entire gather for each window. The amplitudes are normalized by their corresponding threshold value, defined by Equation 10, so this data is not a standard amplitude distribution. It is a distribution of the ratios of the frequency band amplitude to threshold amplitudes. Each value of the output trace is the number of frequency bands that had a particular amplitude to threshold ratio, and can be used to help determine threshold factors (THRESHOLD_FACTOR parameter). (10)