Correcting seismic data for the effects of the earth's near-surface remains a significant problem in seismic processing, especially for data from areas with particularly difficult surface conditions, such as the presence of permafrost. Earlier work has introduced the concept of generalizing statics corrections from simple time shifting of seismic traces to a deconvolution process aimed at removing "statics distribution functions" from the traces. In addition, the notion of raypath angle dependence of near-surface corrections was introduced for those situations when the near-surface velocity exceeds that of deeper bedrock.
This work revisits the raypath-dependent statics concept, illustrates a processing flow for determining the raypath-dependent statics functions and removing them, and discusses the rationale behind the processing. The University of Calgary Hansen Harbour seismic data set, in spite of its relatively small statics, was used earlier to illustrate the process. A second example is shown here, a high resolution data set contributed by Shell. This example provides a more compelling result while also illustrating some of the problems with the technique which remain to be resolved.
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