| Abstract: | A method is presented to derive approximate versions of the wave equation which allow finite-difference migration for very steep dips (> 50°). It is shown that for conventional finite-difference schemes, in addition to the dip limitation, the maximum acceptable frequency should be specified. A finite-difference migration technique is proposed in the frequency domain. It is derived that finite-difference wave field extrapolation in the frequency domain consists of a space-variant convolution procedure for each frequency component, the space-variance being defined by the lateral variation in the velocity. Finally it is shown that with finite-difference migration, particle velocity data can be easily obtained from pressure data. |
