Time‐frequency pattern of the sound intensity fluctuations of midfrequency signals in presence of internal waves in Shallow Water 06 experiment.

Abstract

In given paper fluctuations of intensity of sound signals, radiated by the midfrequency source (R/V Knorr) during ∼5 h were studied. Broadband signals (2–8 KHz) were received by four single hydrophones fixed at the bottom (SHRUs) placed at different distances from the source (from 4 to 12 km). These four acoustic tracks have different directions relative direction of propagation of the train of intensive internal waves (the corresponding angles in horizontal plane are from ∼5 to ∼15 deg). Time‐frequency diagrams were constructed using frequency filtering of the spectrum of broadband signals with sliding narrow window. Temporal dependences of intensities of received signals within frequency window were constructed for period 14:00 until 19:00 GMT for experiment carried out on 13 August. During this time train of internal solitons was registered, propagating toward the coast. Mentioned time‐frequency diagrams demonstrate specific features of influence of internal waves on the temporal variations of the soun...