Review the ultrasonic scattering model for inhomogeneous soft tissue;

So, to have a deeper knowledge about fish school scattering problem and provide a theoretical support for the fish finder development, some efforts are made as follows:The single fish model is the base of fish school acoustic scattering model.

A bistatic scattering model is presented based on perturbation theory and empirical formula in this paper, and the relations between the bistatic scattering strength and the frequency, the wind speed, the sound speed, the angles(the grazing angle, the scattering angle and the bistatic angle) are analyzed by means of computer simulatio.

The model is applied to shallow water with a reverse thermocline and the curves of reverberation loss calculated by the model are compared when applying four different bottom scattering models.

In order to study bistatic ocean reverberation,three bistatic scattering models are developed.

Firstly,the range parameter of scattering centers is obtained by matrix-pencil method,and the type parameter of scattering centers is estimated based on approximation of GTD scattering model,and then the amplitude parameter of scattering centers can be estimated by least-squares method.