This trace processor simulates the 4D response of seismic at a particular cross line and sample range as selected by the user. For the relevant data (samples 495 - 575 that have cross line values higher than 1609), the negative amplitudes are multiplied by a random scalar ranging from 0.6 to 0.8, effectively dimming the amplitude of the negative sample values. Positive amplitudes are multiplied by a random scalar ranging from 0.8 to 0.99, effectively also dimming the amplitudes of the positive sample values but to a lesser extent.

This is the baseline survey:

This is the modeled monitor survey, which is the baseline survey + Python processor to simulate a 4D response. See cross line values > 1609, and see the dimming that is evident near 2.2 seconds.