Modelling of elastic wave propagation in random media : validation and inversion issues

摘要

Wave propagation in heterogenous media is a challenging issue for numerical simulation. Indeed phenomena ranging from guided waves, single and multiple scattering, diffusion or localization are difficult to capture using numerical techniques because of: radiation conditions at infinity, the large range of scales involved, the randomness of the propagation medium, the effect of the spatial dimension on the different propagation regimes. In addition to the related numerical difficulties, the validation of such numerical models cannot be done using closed-form solutions. The only amenable validation strategy consists in using theoretical asymptotic results at large propagation time or peculiar properties such as time reversal or theWard identity. This paper reports several attempts toward the validation of such numerical models and some new results on asymptotic solutions in random anisotropic media.