Objectives  In order to further improve the accuracy of torpedoes in the acoustic homing identification of complex surface targets, a simulation study on the acoustic scattering characteristics of surface ship motion attitudes in random waves is carried out.

  Methods  To effectively solve this problem based on Kirchhoff approximation theorem and six-degrees-of-freedom (DOFs) motion decomposition and synthesis method, a simplified prediction model for the multi-path acoustic scattering of surface targets is established. In this model, the effects of sea waves on the amplitude and period of a ship's six-DOFs motion are described by empirical statistics, and the rotation matrix and translation matrix are used to realize the coordinate transformation of each vertex of the surface target in a continuous motion state. On this basis, the model is used to analyze the contribution and influence of six-DOFs motion attitudes on the acoustic scattering characteristics of a surface ship from different horizontal detection angles.

  Results  The results show that the rolling and yawing motions have a great influence on the acoustic scattering of the target in the abeam detection, while the pitching motion has a great effect on the acoustic scattering in the bow and stern directions. Thus, the relationship between the surface ship's motion attitudes and acoustic scattering echoes is grasped.

  Conclusions  This study can provide technical support for sonar equipment in the location and identification of surface targets.