The imaging operator I chose to use is the downward continuation migration described in Prucha et al. (1999a,b). To summarize, this migration is carried out by downward continuing the wavefield in frequency space with the Double Square Root (DSR) equation, slant stacking at each depth, and extracting the image at zero time. In 2-D, this process can be described as:
The resulting image has the dimensions of depth (z), common reflection point (CRP), and offset ray parameter (ph).
The result of carrying out this migration on the synthetic dataset can be seen in Figure . The stacked image (top panel) shows the shadow zones that we expect beneath the salt edges. The lower panel shows 10 different ray parameters gathers taken from between and . There are definite variations along the flat events that can also be attributed to illumination problems.