Disclosed is a method for characterizing the evolution of a sub-surface volume. The method comprises providing a first and second surveys of the reservoir with a first and second sets of seismic traces, constructing an analytic filter operable to shift one or more seismic traces in dependence of a model parameter; and performing an inversion to obtain estimates of the model parameter such that the analytic filter aligns said first survey and said second survey. The analytic filter may be a plane wave destruction filter, and be such that the model parameter is a function of the analytic filter and is not a function of one or more of said second set of seismic traces.