Estimation of underwater acoustic fields at high frequencies

In this work a parametric modeling of the underwater acoustic field is investigated in a laboratory scale at high frequencies (150-850 kHz). The aim is to develop experimentally verifiable theoretical models to investigate the acoustic field propagation in elastic and viscoelastic or porous media. To achieve this goal, the efforts have been directed to three integral parts pertaining to the development of the methods. The first part deals with the modeling of the underwater acoustic field following different approaches. The second treats the development of an efficient estimator to identify the model parameters from the experimental data. The third and the final part Is the experimental verification of the theoretical approaches. Two new but different approaches are investigated and compared for the modeling of the bounded field diffracted In a water medium. Once the parametric models for the Incident underwater acoustic field are determined, the application to the estimation of acoustical properties of viscoelastic or porous media by transmission or reflection measurements is carried out