Abstract：Ordinary DMO processing methods neglect the influence of velocity because some people think that DMO processing is less sensitive to velocity than full migration processing.As a matter of fact,under certain circumstances,DMO processing must consider velocity effect to avoid bad result in seismic data image.Variable velocity DMO formula which is analogous to constant velocity DMO formula and Hale' s squeezing DMO is derived from the time-distance equation of CRP gather data.The method is a revised version of constant velocity DMO;and it is equivalent to constant velocity DMO in computation efficiency,but superior to constant velocity DMO in processing result.Theoretical and real processing results show that the method is very suitable to the image of steep-dip seismic data in the area where seismic velocity varies with depth.
