The objective of the present work is to obtain estimates of the P- and S-wave velocities and densities of the subsurface. The inversion is carried out on 952 τ – p transformed CMP gathers, each containing 61 p values ranging from 0.05 to 0.35 s/km.

The forward modeling is performed by convolving the reflectivity with the wavelet, and it includes water bottom multiples, transmission effects, absorption and array filter effects. The basic assumption is that the subsurface is close to horizontally layered. A damped Gauss-Newton algorithm is used to minimize a least-squares misfit function.

Comparison with the...