Use of frequency domain analysis for signal-to-noise ratio enhancement in stacking

An algorithm is presented for the stacking of seismic CMP (common midpoint) gathers. It is characterized by improved signal-to-noise ratio over the conventional method. The procedure is based on the principle that Fourier coefficients that contain more noise than signal should be excluded from the stacked trace. This selective process is accomplished by means of coherency coefficients aimed at estimating the phase agreement among Fourier coefficients of traces in the gather. It is concluded that while this selective stacking procedure requires an excessive amount of computation in comparison with conventional stacking, in some situations it may be the only viable alternative to improving the signal-to-noise ratio. Synthetic seismic data are used to demonstrate the stacking scheme and its improved noise-reduction capability