Low-frequency ocean acoustics
The most important part of basic and applied scientific research of the IAP RAS is the low-frequency (LF) hydroacoustics. The activities in this field are a successful continuation of the applied hydroacoustic studies performed at the RRI as early as in the 1960—70s under the guidance of professor V. A. Zverev who is now a corresponding member of the RAS. It is known that acoustic signals in the range of tens and a few hundred hertz are the most effective "tool" for diagnostics and monitoring of the ocean on large scales, i.e., to thousands of kilometers. Thus, from the first years of work in this field, the IAP RAS develops methods and facilities for active diagnostics of the ocean, based on high-power coherent hydroacoustic sources whose signals "illuminate" the ocean depth and make "visible" the inhomogeneities of the water column or the objects moving in it, which scatter this radiation and direct it towards receiving systems. The concept of active LF sonar detection or illumination of the underwater environment was proposed by academician A. V. Gaponov-Grekhov and reliably substantiated by successful field experiments and theoretical studies carried out by the Institute scientists in different years. The Institute is now the leading national and worldwide developer of active LF sonar systems, namely, from physical principles to technical implementation in the form of emitting complexes and receiving antenna systems needed to conduct field experiments.