Introduction

The Dip Moveout correction (DMO) is an intermediate processing step which when applied together with the Normal Moveout correction (NMO) transforms a constant-offset section into a zero-offset section. There are many benefits to introducing the DMO processing step. Perhaps the best overall quality is the fact that it is a very robust process. It needs very few parameters and almost always improves the output section.

By applying the succession of DMO, NMO, stacking and zero-offset migration we replace the more expensive sequence of prestack migration for each offset and stacking. However the migration to zero-offset is not the only improvement that DMO delivers to the seismic section. A list of DMO promises is given by Deregowski (1986) and includes improvement of velocity analysis, dead traces interpolation, improvement of cross-line ties, steep dip coherent noise attenuation, improvement of the signal to noise ratio, diffraction preservation, etc. These beneficial effects will be discussed further.