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** Up:** Multiple attenuation results
** Previous:** Inside the salt boundaries

I now compare the stacked sections for the three techniques in Figure
. These figures are clipped to the same
value for direct comparison. It is clear from Figure
that the best multiple attenuation result is
obtained with the pattern-based technique with 3-D PEFs. Then comes
the pattern-based method with 2-D PEFs, then the adaptive subtraction
and the HRT. The HRT is simply unable to correctly attenuate multiples
in the complex area defined by the salt boundaries. However, it does a
fairly good job outside the salt boundaries. The quality of the
adaptive subtraction method is hampered by modeling uncertainties,
especially where the diffracted multiples are the strongest, i.e.,
between four and five seconds.
It is pleasing to see that the pattern-based method, while preserving
the primaries, removes the diffracted multiples very well. The multiple
attenuation result with 3-D filters is even more striking: the
diffracted multiples are almost completely gone (see at four seconds).
Although the model of the multiples is not perfect, there is enough
resemblance between the ``real'' diffracted multiples and the modeled
ones across dimensions to obtain a satisfying attenuation.

As a final comparison, I show in Figure the
stacked sections of the removed multiples for the three methods. It
shows that the pattern-based approach with 3-D filters removed more
multiples than any other method.

**compstack-multatt
**

Figure 6 Stacked
sections of the estimated signal. (a) Adaptive subtraction
result. (b) HRT result. (c) Pattern-based method result with 2-D
PEFs. (d) Pattern-based method result with 3-D PEFs.

**compstack-diff
**

Figure 7 Stacked
sections of the removed multiples. (a) Adaptive subtraction
result. (b) HRT result. (c) Pattern-based method result with 2-D
PEFs. (d) Pattern-based method result with 3-D PEFs.

** Next:** Discussion-Conclusion
** Up:** Multiple attenuation results
** Previous:** Inside the salt boundaries
Stanford Exploration Project

7/8/2003