CHARACTERISTICS OF OPTIMUM MULTICHANNEL STACKING FILTERS

Abstract

A large class of seismic processing operations involve the linear combination of several traces in such a way that certain “signal” events are emphasized over other “noise” events. If the noise events are randomly distributed between traces, then simple addition of the traces represents the best possible technique for suppressing the noise. However, in many cases a noise event on one trace will also occur at relatively well‐determined points on other nearby traces. For these cases, multichannel linear filters offer better discrimination against organized noise than the straight addition of traces does. Such multichannel filters can be designed with only a knowledge of the relative times of the arrivals for the various signal and noise events but with no knowledge of the actual event shapes. In addition, the filter may be specified to allow for such contingencies as the presence of random noise, variable gain between traces, and random variations of the relative time of arrival between traces. Once these parameters have been specified, the optimum linear filter may be computed. A suite of test computations has provided a set of generalizations which aid in the design of this type of filter and indicate that optimum multichannel linear filters can be far superior to straight addition for a wide class of organized noise.