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Correlation analysis of low-frequency reverberation signals has been carried out by decomposing the reverberation into reference functions, formed as a set of signals reflected from a point scatterer moving along a circular trajectory. The choice of the reference signal is related to the model of sound scattering by inhomogeneities (bubbles) occurring in the near-surface layer and moving together with the orbital currents of wind waves. The study demonstrated that the correlation functions differ significantly (by 5–6 dB) for the region of position and negative Doppler frequencies of reverberation signals. A stable increase has been revealed for the maximum of the correlation function at certain radii of scatterer motion, which are related to the amplitudes of wind waves.

The paper describes the results of an experiment on studying long-range surface reverberation in the deep-water part of the Black Sea. The experiment employed tone pulses with a filling frequency of 2 kHz and a duration sufficient for narrowband spectral analysis. The source and receiver of acoustic signals were spatially offset in the water area; therefore, directional reception and time strobing made it possible to study different situations: forward scattering, bistatic scattering, and monostatic (back) scattering. The paper analyzes the Doppler scattering spectra for different values of the bistatic scattering angle.