Underwater acoustic scattering of a Bessel beam by rigid objects with arbitrary shapes using the T-matrix method

The T-matrix method has been extended to compute backscattering of rigid structures by a Bessel beam, which is a kind of approximate non-diffracting beam and characterized by the cone angel of its plane wave components. In this work, backscattering of underwater rigid spheroids and finite cylinders with spheroidal endcaps were calculated. The backscattering form function modulus |F| is curved as a function of dimensionless frequency ka. Meanwhile, the peak to peak intervals in backscattering form function caused by the interference of the specular wave and the Franz wave have been analyzed in geometry, so as to the relation with the cone angel of the Bessel beam. The work of this paper could be helpful to the applications of Bessel beams on the acoustic detection of the submerged complex-shaped objects.