Determination of the Primary Classification Characteristics of Monochromatic Sound Source in Shallow Sea

The work is devoted to the problems of determining the primary classification characteristics of a controlled autonomous underwater technical means, as well as searching for and clarifying the features that make it possible to determine the position of the indicated object in the shallow sea by the stationary signal system adopted. Based on the model of shallow sea, given by the classical flat regular waveguide with combined boundaries (the bottom is presented as an acoustically hard border, and the surface is served as an acoustically soft border), special points of the vector field of the intensity of the sound signal are considered. This signal is created by a monochromatic point source, which moves evenly and straightforwardly, and is fixed by a stationary reception system, which can contain one or more receivers of a certain physical nature. Connection of the type and location of special points of the field and the deviation characteristics of the signal recorded by the combined receivers is established. It is established that the constancy of the vector distribution of the intensity field and the positioning of the corresponding singular points in the waveguide sections is maintained at the change of the source horizon in certain limits of the depth of the waveguide when deduced from the bottom and when deduced from the surface. The results of calculations of the vector field of intensity and deviation characteristics of the received signal corresponding to a certain set of such initial conditions as the depth of the sea, the frequency of the carrier wave of the source (from the region of the boundary frequencies of the waveguide) are given. In this case, the correspondence of such parameters of the received signal as the sign, the magnitude and periodicity of the deviations of the wave-carrier frequency is established by a certain distribution of the vector intensity field. An unequivocal connection is also established between the results of the analysis of the deviation characteristics and the horizons of the location of the sound source (which corresponds to the primary classification criteria of the source). An example of the implementation of the inserted classification features for the application of two pressure receptors located in the bottom area on defined horizons is provided and the frequency deviation registration is provided. This allows you to not record the value of the intensity field. In this case, the general regularity of their work is revealed and described in detail. Ref. 10, fig. 11.