A frequency domain inversion method applied to propagation models in unconsolidated granular materials

The measurement setup consists of a water filled tank within which a smaller Plexiglas tank containing a known sediment is placed. This provides a Plexiglas-sediment-Plexiglas configuration, which is then used in conjunction with transducers and a pulser-receiver for a transmission and reflection experiment. The aim of this work is to find some physical parameters of the sediment from these measurements. A general viscoelastic model that considers losses due to absorption and dispersion along the propagation of the wave through the sediments is proposed. A rational transfer function is used to model the viscoelastic modulus of the bulk sediments, and comparisons with constant Q viscoelastic modelling and Biot modelling are performed. The estimation of the model parameters is elaborated using a maximum likelihood estimator in the frequency domain.