Correlation processing of a noise signal in the arrival-time acoustic monitoring of the water medium in an arctic waveguide

The propagation of a noise signal is considered for an arctic-type waveguide with a varying sound speed profile. The profiles used in the calculations differ from each other due to different depth dependences of salinity. The shape of the envelope of the time correlation function is studied for the coherent and reference signals. For the latter, either the replica of the transmitted noise signal or one of the modes propagating in the waveguide is used. A characteristic feature of the proposed technique is the use of the time cross-correlation between the signals that traveled through the same path in the presence of different sound speed profiles. In this case, from the shape of the envelope of the signal correlation function, one can estimate the changes that occur in the sound speed profile on the path of signal propagation.