f Depth focusing analysis: The effects of elevation corrections and structural DIP

Prestack depth migration, combined with depth-focusing analysis (DFA), is a useful method for imaging and velocity estimation in areas of complex structure. However, such regions often possess significant topographic relief that leads to large elevation-static corrections prior to migration. The result is a distorted wavefield that yields erroneous depth-focusing information. Of further consequence are the limits imposed by the zero-dip approximation to the wave equation used for velocity estimation.