Sound field structure produced by tone sources in the Kurile-Kamchatka region of the Pacific Ocean with a surface channel and wind waves

Results of the experimental studies of sound signal propagation in the continental wedge of the northwestern Pacific, near the eastern coast of the Kamchatka Peninsula, are presented. The signals are produced by highly stable tone sources. The experiments are carried out in winter, in the presence of a strong surface sound channel and intense wind waves, at frequencies of 100, 230, and 400 Hz, on a 1000-km-long path. The signal transmission is performed by continuously towing the sound sources at a depth of 50±5 m with a speed of 4.5–5 knots, for 115 hours. The decay of the sound field level with distance is studied as a function of the sea state and the frequency. The results of the experiments, including the sound field decay along the path, are compared with the calculations for different sea states.