P177 Pattern-Based Compensation for Signal Distortions in 3D Kirchhoff Depth Migration M.S. Denisov* (GeoTechSystem Ltd) S.L. Langman (GeoTechSystem Ltd) & D.B. Finikov (GeoTechSystem Ltd) SUMMARY Many seismic data processing techniques (pre- and post- stack migration redatuming forward and inverse wavefield extrapolation multiple prediction etc.) apply spatial summation of seismic traces. A wellknown fact is that the shape of the seismic wavelet is degraded by such summation. Hence these procedures should be equipped with a compensation filter. The conventional filter design (Claerbout 1984) leads to an operator that is stationary with respect to both time and spatial coordinates. On the other