A method for attenuating undesirable data, such as multiples, using constrained cross-equalization.

摘要

To eliminate undesirable energy recorded during seismic surveying, a trace that models the undesirable energy on the recorded data trace is prepared. The model trace is first estimated using a suitable technique, such as wavefield extrapolation. Then, the model trace is modified using a best estimate of the amplitude, phase and time delay differences between the model trace and the data trace. The estimated amplitude, phase and time delay differences may be used to design a cross-equalization filter, which is used to cross-equalize the model trace with the data trace. Alternatively, the best estimate determination may include using a weighted sum of the model trace, its imaginary component, and their derivatives. When weighted and summed together, these components form a cross-equalized model trace that closely approximates the undesirable energy on the recorded data trace. Lastly, the cross-equalized model trace is subtracted from the data trace to substantially eliminate the undesirable energy.