Conclusions

Non-diffracted water-bottom multiples, whether from a flat or dipping water-bottom, map to zero or negative subsurface offsets when migrated with the velocity of the sediments $\rho\gt 1$ for $h_D\ge 0$. On the other hand, primaries migrated with slower velocities map to positive subsurface offsets. It may be possible to exploit this fact to attenuate these multiples.

Diffracted water-bottom multiples, in contrast, map to both positive and negative subsurface offsets depending on the relative position of the CMP and the diffractor. To attenuate these multiples we need an accurate representation of their residual moveouts in either SODCIGs or ADCIGs as presented here to design a suitable Radon transform that focuses these multiples to predictable locations in the Radon domain. This is the subject of ongoing research.