Dispersion Correction Based on Gradient Computations

P302 DISPERSION CORRECTION BASED ON GRADIENT COMPUTATIONS Abstract 1 Time delay evaluation is an essential operation often necessary in multidimensional signal processing. Into seismic processing this operation is carried out in a systematic way before wave separation filter. All these operations and especially wavefield separation tools are very sensitive to a good wave alignment. Conventional time delay estimation relies on cross correlation or less classically on high order statistics. Nonetheless in near surface applications modeling the propagation by a simple delay may be not enough. In this paper we approximate the phase of the propagation filter at the order two