Raypath statics revisited: new images

David C. Henley

In previous work, we have shown that near-surface effects, principally static shifts, can be largely removed from seismic data using two novel concepts: finding and deconvolving `statics distribution functions' from the traces; and transforming the input data to the radial trace domain, where near-surface effects can be separated by their dependence upon raypath angle. We have demonstrated our techniques via several procedures implemented in ProMAX, using two data sets from the Canadian arctic, one of which manifests very large near-surface effects due to river channels. For the latter data set we were able to improve the coherence and continuity of the near-surface layers on the seismic image; but not that of deeper, more structured layers. In this report, we describe an extension of the technique, for which we can improve the continuity, not only of the shallow layers, but the deeper structure, as well. We also issue a warning about a possible pitfall of this technique.