Examination of the broadband low-frequency emitters in the study of temperature regimes in the Sea of Japan

The use of technical means and methods of low-frequency hydroacoustics for monitoring the variability of average temperatures of underwater sound channels in the Sea of Japan is considered. A review of the characteristics of the line of powerful inter-piston hydroacoustic emitters developed by the Institute of Applied Physics of the Russian Academy of Sciences, developed by the Institute of Applied Physics of the Russian Academy of Sciences, is carried out, promising for organizing long acoustic routes. The results of measurements of the electroacoustic characteristics of low-frequency hydroacoustic emitters under natural conditions at depths of up to 150 m are presented, and the use of these emitters for studying the temperature regimes of associated underwater sound channels of the shelf and deep sea on multi-scale long routes in the Sea of Japan is also considered. Based on the processing of experimental data on an acoustic path with a length of about 1000 km, obtained in 2022, examples of the reconstruction of average water temperature values from data on the speed of sound along the acoustic path are given, the sensitivity of the method is assessed, and the signal-to-noise ratio values achieved in the experiment are analyzed.