最近几年来,由于牵引式声纳器的问世,在潜艇探测技术方面发生了革命性的变化。它是由一系列排列在电缆上的无源水听器组成,装在舰船的尾部,随船航行。这种声纳器的妙处在于它不受牵引船只发出的噪声干扰,而对在遥远的海中传播的低频声波有独特的捕捉能力。要是碰巧的话,最先进的声纳探测器可以测出停泊在离它二十英里处的潜艇,如果潜艇在海底航行,那末这种声纳器探测的距离还可增加五倍到十倍。 In recent years, with the advent of tractive sonar, a revolutionary change has taken place in submarine detection technology. It consists of a series of passive hydrophone arranged on the cable, installed in the tail of the ship, sailing with the ship. The beauty of this type of sonar is that it is not disturbed by the noise emitted by the towing vessel and uniquely captures the low-frequency sound waves that travel in the distant sea. If, by chance, state-of-the-art sonar detectors detect submarines parked twenty miles away, the sonar can detect five or ten times more range if the submarine sails underwater.