Fast energy-minimization method : For surface-related-multiple removal

in which the time-domain counterpart of Eq. (2) is substituted. This criterion is minimized by a Monte-Carlo type A fast and efficient optimization procedure is presented to meet the minimum-energy criterion for the determination of the source wavelet in the process of elimination of surfacerelated wavefield phenomena. The energy criterion is formulated in the frequency domain and a minimization over all frequencies and traces is taken as point of departure. A modified conjugate-gradient iterative method for the non-linear optimization problem is presented, where the conjugategradient directions are chosen in such a way that, at each iteration, the causality of the unknown source wavelet is enforced. The method is applied to marine seismic field data and leads to satisfactory results. of procedure, with a computationally time-consuming procedure of switching between the frequency domain and the time domain.