Rigid and elastic acoustic scattering signal separation for underwater target.

Underwater target elastic acoustic scattering and other acoustic scattering components are aliasing together in the time and frequency domains, and the existing signal processing methods cannot recognize the elastic scattering features under the aliasing condition because of the resolution limitation. To address this problem, this study, which is based on the target echo highlight model, analyzes the characteristics of target acoustic scattering components when the transmitted signal is a linear frequency modulation pulse. The target acoustic scattering structure in the fractional Fourier transform (FRFT) domain is deduced theoretically. Then, filtering is used in the FRFT domain to separate the target elastic acoustic scattering components. In addition, noise suppression performance and filter resolution are discussed. The target rigid and elastic acoustic scattering components are separated. Experimental results show that filtering in the FRFT domain can separate the elastic scattering components from the target echoes. Moreover, separated elastic acoustic scattering components have consistent theoretical features, which lay the foundation for studying the elastic scattering characteristics further.