Beam steering after surface noise suppression

Figure 15 shows the result of beam steering the data after the first pass of surface noise suppression, where a single recorded trace was used as the source waveform. Figure 16 shows the result of beam steering after the second pass of surface noise suppression, where the source waveform was computed by stacking along the surface noise source's moveout trajectory. Note the dark areas in the upper left of the plots in Figure 16; these are not large semblance values which have been clipped, but the small semblance values that remain after surface noise suppression has done a very good job.

It is interesting to note that beam steering suggests that the second application of surface noise suppression was much more effective, while the semblance results for the two applications were comparable. Perhaps an improved method of estimating the source signal would improve both results.

 

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Figure 15 Beam steering after the first pass of surface noise suppression. The algorithm has done a reasonably good job of suppressing the surface noise source in the upper left. Other plane waves at higher apparent velocities are relatively enhanced by the suppression of the surface source.

 

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Figure 16 Beam steering after the second pass of surface noise suppression, where the source waveform was created by stacking along the moveout trajectory of the surface source. Now the algorithm has done a much better job of suppressing the source, at least in Record 3. The dark area near the upper left is not large amplitudes that have been clipped; it is the small amplitudes that remain after the surface source has been removed very well.