Broadband classification of submerged targets

A recently proposed echo analysis scheme, based on a polynomial model of the target transfer function and an optimally Doppler tolerant transmitted waveform is applied to relatively low frequency broadband echoes from a number of simple submerged targets. It is demonstrated that such a model only represents the gross characteristics of the target transfer function not the detailed resonance structure necessary for classification and that the description most commonly used in sonar for distributed targets (an array of point scatterers) represents the targets examined more efficiently than the proposed model. An iterative procedure for generalizing and improving the polynomial model is introduced and discussed.