Decoying acoustic homing torpedoes

摘要

1. Apparatus for protecting a pelagic vessel from attack by acoustic homingorpedoes comprising a vehicle to be towed submerged a substantial distance behind said vessel, an electroacoustic transducer mounted in said vehicle and having a forwardly directed directivity pattern, a source of constant amplitude oscillating electrical wave energy, means for modulating the oscillating frequency of said wave energy cyclically over a range inclusive of the operating frequencies of such torpedoes and at a linear rate slow enough to satisfy the energy requirement in the band pass of passive torpedo circuits and fast enough to satisfy the rise time of active torpedo discriminator circuits, and means for energizing said transducer with the modulated wave energy from said source.