Velocity Inversion Using Waveletrepresented

If we assume that the velocity proole is an image that can be compressed greatly using wavelets, then a relatively smaller wavelet represented model can be equivalent to a larger physical model; we obtain the modiied Bleistein/Cohen (BC) inversion formulation by restricting the perturbation to the smaller wavelet represented model. The method demonstrates three important features: rst, the BC technique can be modiied easily; second, much larger inverse problems can be solved since they are greatly reduced; third, ill-posedness can be alleviated by ladder inversion, i.e. inversion from low to high wave number versions.