CONCLUSIONS

We have presented an approximate solution to the problem of varying fold in 3D subsets extracted from 5D prestack volumes. The solution is based on a multiplicity concept that normalizes each input trace by the local fold of its corresponding bin. The technique represents a new development in our proposed strategy for processing wide-azimuth surveys for amplitude inversion. Results of the application of integral migration and integral AMO as discrete summations over the preconditioned data have proved to correct and equalize the imaging process for the effects of irregular fold. The advantage of applying the normalization procedure at the AMO stage is threefold: (1) reduction of the size of prestack data subsets (2) interpolation to a regular grid before imaging (3) common-azimuth common-offset processing of the 3D survey. Moreover, if we consider processing to be the inverse of modeling irregular data from a regularly-sampled model, AMO can be used to formulate a general inversion scheme for 3D models from irregularly sampled data. The limited small aperture of AMO enables inexpensive implementation of the inversion algorithm. The equalization technique could be used for preconditioning the inversion by column scaling under the assumption of small variations in azimuth and offset. This is the subject of continuing work and a full algebraic description of the solution will be presented in subsequent reports.