Robustness in Ray Reflection Tomography for Laterally Varying Media

In this paper we show that when we work with a basis of Bsplines defined by a convenient set of knots, for laterally velocity functions, large offsets and with soft constraints imposed in the Tikhonov's sense [Tikhonov, 1963], we can get excellent results applying Ray Reflection Tomography for kinematic interpretation of seismic records. We propose a method whose robustness is well illustrated by a synthetic application where a geological model described by fifty-four B-splines coefficients is reconstructed in up to three iterations from very different initial guesses, which are defined through the application of the Dix type approach [Goldin, 1986J for several sets of CMP gathers. The regularization matrices are defined by analysing the level curves of the resolution matrix elements interpolation [Soares, 1994].