After applying the first step of shot-profile migration (source and receiver wavefield construction) the dimensionality of the data increases. Thus, for each shot position (xs,ys) the source and the receiver wavefields and are defined in four dimensions (Figure ), where (x,y,z) are the image space dimensions.
Figure 1 Data dimensionality. The source and receiver wavefields are 6-D datasets.
In the following analysis, we explain how to combine the source and the receiver wavefields to obtain an image. For simplicity, we restrict our analysis to 2-D prestack data. In this case, the source and the receiver wavefields are 4-D datasets defined in (x,z,t) for each shot position xs.