Fluctuations of an intensity of the broadband pulses are studied in mid-frequency area (2-4.5 kHz) propagating in the shallow water in the presence of intensive internal waves (IW) moving approximately along an acoustic track. Theory elaborated earlier predicts that in this case specific features of fluctuations are provided by modes coupling (for low frequency sound) or ray scattering (high frequency area) and depend on direction of propagation of signals relative wave front of IW. The corresponding research was carried out during multi-institutional experiment SW06 in New Jersey shelf. We analyze temporal dependence of intensity for the sequence of the sound pulses radiated from the R/V Knorr during approximately one hour-15:31-16:20 GMT (August 13, 2006) and received by two separate single hydrophone units (SHRUs) placed at different distance from the source (4 km and 12 km). The corresponding acoustic tracks had a little different directions relative wave front of IW. Properties of IW were established using temperature records of sensors in different locations. It is shown that frequency spectra of fluctuations for these SHRUs have different predominating frequencies in accordance with mentioned directions of acoustic tracks. Results of measurements are compared with theoretical estimations and demonstrate good consistency.

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