Optimal trajectory for swim-out acoustic decoy to countermeasure torpedo

The optimal trajectory of a swim-out acoustic decoy defending against an acoustic homing torpedo is studied. First, the dynamic models of the torpedo and submarine, and several trajectory models of the decoy are established. The factors that affect the countermeasure effectiveness are analyzed. Then based on the assessment criterion, genetic algorithm is used to obtain the optimal parameters of the trajectory models under different cases. Simulation results show that the helical and circular models of decoy trajectory are dominated by three other models, i.e., straight line, second turn-angle and snake trajectory.