Passive target classification based on mode energy difference characteristic of the wavenumber spectrum

Underwater target discrimination plays an important role in military defense and attack, this paper proceeds with the acoustic field wavenumber spectrum difference excitateded by the surface target and underwater target, a method of passive target classification based on mode energy difference characteristic of the wavenumber spectrum is proposed. Firstly, according to wavenumber integration acoustic theory, an approach to sound field wavenumber spectrum acquisition method by horizontal arrays is introduced. Secondly, combined with ray acoustic model and normal mode acoustic model, the difference character of acoustic spectrum between surface target and underwater target is quantitative analyzed, the wavenumber spectrum energy difference character which can distinguish surface target and underwater target is excavated, its acoustic physical nature character is the energy ratio between low-rank and high-rank normal mode in wavenumber spectrum. At last, a method of passive target classification based on mode energy difference characteristic in the wavenumber spectrum is proposed; several numerical simulations of typical conditions are tested. The simulation result shows that, by extracting the mode energy difference characteristic to discriminate the surface target and underwater target is valid, and this method is robust with various environments. The method proposed by this paper may provide a novel way to the problem of underwater targets classification and recognition.