Objective  In order to further improve the speed and accuracy of calculating the acoustic scattering fields of underwater concave targets, the acoustic scattering characteristics of underwater corner reflector complexes are studied.

  Method  By applying the Kirchhoff approximation and ray tracing methods, and considering the multiple effects of scattering and occlusion by corner reflectors, a simplified acoustic scattering prediction model of an underwater corner reflector complex is established and a rapid prediction method （i.e. modified planar element method, PEM）of acoustic scattering fields is proposed. The acoustic scattering field of a corner reflector complex is calculated by this method and verified via finite element simulation; on this basis, an analysis is made of the characteristics of octahedral corner reflectors, combined polyhedral corner reflectors and cluster-based and space-based strong scattering targets.

  Results  The results show that the modified PEM allows the rapid and accurate calculation of the acoustic fields scattered by diagonal reflectors. The acoustic scattering fields of octahedral corner reflectors and combined polyhedral corner reflectors varies with the incident wave frequency, angle and reflector complex distance.

  Conclusion  The results of this study can provide important technical support for the design of underwater passive interferer models.