Target classification near complex interfaces using time-frequency filters

This paper presents a method for target recognition and clas-sification in shallow water environment. It is based on time-frequency filtering matched to a free field reference target response. The decision strategy lies on the comparison of the reference and the filter output signal. The method is ap-plied to an experimental data base containing target acoustic responses measured in a tank for typical configurations (free field, semi-infinite space and waveguide). First, the recog-nition of a spherical shell is carried out. The obtained rate of recognition and confusion are more than encouraging. Then, a classification procedure is conducted and a degra-dation of the mean performances is to be noted in the more general case. However, the classification of 3D targets in-dependently of their attitude gives quite satisfactory results. 1