Abstract: In one embodiment, a computer-implemented common azimuth migration seismic data processing method comprises: providing a common-azimuth input data set for a geophysical data processing volume of interest; providing a velocity model for the volume; applying an offset antialiasing operator to the input data set; and performing a recursive downward-continuation of the common-azimuth input data set to a plurality of successive common-azimuth surfaces to generate an image of the volume of interest. In one embodiment, the present invention further provides for selecting a depth dependence of an offset range employed in the downward continuation; selecting a frequency-dependence of a depth step size employed in the downward continuation; selecting a frequency dependence of a cutoff depth employed in the downward continuation; and adding reciprocal traces to the data around zero offset, for reducing imaging artifacts introduced by data edge effects.

Abstract: Input seismic data are re-gridded to an arbitrary output grid by output-based azimuth moveout. An input seismic data set corresponding to an input grid is used to generate an equivalent output seismic data set corresponding to an output grid different from the input grid. Preferably, the output grid is divided into blocks, and each output grid block is assigned to one of a plurality of independent parallel processors. For each output trace corresponding to an output location, the contributions of plural input traces to the output trace are computed according to an azimuth moveout operator. The contributions are then summed into the output trace.