METHOD FOR REDUCING NOISE IN SEISMIC SIGNALS BY ADAPTIVE FILTERING OF A NOISE REFERENCE

摘要

A method of reducing effects of noise in seismic signals generated by a plurality of seismic sensors at spaced apart locations from a seismic source is disclosed. Each of the signals is represented by a signal trace in a record section. The method includes the steps of isolating noise in the signal traces, time aligning corresponding portions of the noise in the traces thereby generating time-aligned noise traces, stacking the time-aligned noise trace to generate a stacked noise trace, replicating the stacked noise trace at each corresponding trace position in the record section, restoring the replicated traces to the original trace time positions by reversing the step of time-aligning to generate noise signature traces, comparing the noise signature traces to corresponding signal traces to generate filters which substantially minimize a measure of the difference between the noise signature traces and the signal traces. The noise signature traces are then filtered and the resulting filtered noise signature traces are subtracted from the signal traces. In a preferred embodiment the steps of comparing, generating filters, filtering and subtracting comprise linear adaptive filtering. In a particular embodiment the step of isolating the noise comprises bandpass filtering the signal traces.