Determination of the mode composition of the sound field with a single-point reception in a shallow sea

A possibility of determining the mode composition of the sound field in a shallow sea is considered. The procedure involves the transmission of a short pulse by a point source and the subsequent reception of this pulse at a single point. It is shown that the problem can be solved by using linearly frequency-modulated broadband pulses at relatively short distances (about 20 km), where the attenuation of the signal is rather weak. To take into account the intramode dispersion, it is proposed to use the value of the dispersion typical of a perfect Pekeris waveguide with a stiff bottom. With the use of the calculations and the experimental data obtained in the Barents Sea, it is shown that the proposed approximation is sufficient to determine the mode composition of the sound field.