A partial DMO Operator for use with the Stacking Velocity Function

Abstract

Dip moveout (DMO) processing is frequently used to enhance stacked seismic sections. All DMO methods strictly require that the input data have been normal-moveout (NMO) corrected using the true medium velocity rather than the stacking (or RMS) velocity function. Unfortunately this is rarely the case in that most data which are input to DMO have been NMO-corrected according to the stacking velocity, in order to maximise semblance on a CMP gather. Such data are incompatible with the basic DMO assumption. Under such circumstances only a partial DMO process, which produces a parabolic impulse response, should be used rather than a full DMO algorithm, such as that of Hale, which entails an elliptical impulse response. The partial DMO operator accounts for the inaccuracy of the velocity information used in the NMO correction, and leads to superior results.