REVERSE-TIME MIGRATION OF SPARSE AND IRREGULAR DATA

We have formulated a new perspective of reverse-time migration by trea ting the recorded seismic traces as distributed sources on the recordi ng topography. Compared with the traditional boundary condition viewpo int of recordings, this treatment no longer stringently requires that there be one trace on every grid point of the recording topography. Th us, sparsely and even irregularly distributed unaliased recordings wit h respect to the fine finite-difference grid, can be directly applied to the reverse-time migration without a priori trace interpolation. In fact the missing traces are simultaneously interpolated during the re verse-time migration due to the self-healing mechanism of waves in pro pagation. This treatment has been applied to both stacked and prestack seismic data. The migration results restore the subsurface structures very well.