Shear wave near-surface corrections in the tau-p domain: a case study

Raul Cova, Xiucheng Wei, Kristopher A. Innanen

Removing near-surface effects in the processing of 3C data is key to exploiting the information provided by converted waves. Receiver-side corrections may need a more accurate approach than source-side corrections due to the complex character of S-wave propagation in the near-surface. In this study a raypath-consistent approach is used to correct the S-wave near-surface effects. This is achieved by transforming the data sorted in receiver gathers to the -p domain and performing cross-correlation and convolution operations to capture and subtract the near-surface effects from the data. Results show that this processing improves coherency and stacking power of shallow and deep events simultaneously. Shallow events benefited most from this processing due to their wider range of reflection angles. We also show how the correction of receiver orientations based on reversing the polarity of one of the ends of the spread does not consider receiver stations offset due to obstacles during the acquisition. A full 2D rotation toward the source, as in 3D-3C processing, was applied in this study to account for irregularities in the acquisition geometry.