Modern Acoustics Science and Technology Series: Hydroacoustics (2nd Edition) systematically discusses the basic theory of modern hydroacoustics from the viewpoint of sound field analysis. This book is divided into twelve chapters. In the first chapter, the information structure of underwater sound field is briefly described, and the sonar equation is established. The second chapter briefly introduces some characteristics of marine medium as underwater acoustic channel. In chapter 3, the basic concept and theoretical method of water sound field are discussed, and the conversion between normal wave and ray is discussed in detail. The fourth and fifth chapters theoretically analyze the typical sound field. In the analysis of shallow water sound field, the "three-parameter" model of boundary reflection loss is adopted, the average field strength structure is discussed by the analysis method of "transition distance", and the "inversion point convergence area" in deep water sound field is analyzed by the normal mode theory. The sixth chapter discusses the background field in the ocean, introduces the theory that the noise field is composed of propagation operators, and discusses the long-range reverberation in shallow water. In chapters 7, 8 and 9, the characteristics of target source, scattering and fluctuation of signal field, numerical prediction of sound field and channel matching are discussed. Chapter 10 and chapter 1 1 discuss underwater acoustic signal processing, focusing on the optimal space-time processing of sound field, and briefly introduce modern underwater acoustic detection system; Chapter 12 discusses some important problems in underwater acoustic transducer, including structural vibration analysis, especially bending transducer, acoustic array and measurement technology.

The first edition of Modern Acoustics Science and Technology Series: Hydroacoustics (Second Edition) was published 198 1 years ago. During this period, the research on hydroacoustics has undergone great changes and development. In order to adapt to the new situation in this field, the second author of the original book revised Modern Acoustics Science and Technology Series: Hydroacoustics (2nd Edition). In recent years, the progress of hydroacoustics has been properly reflected and new reference materials have been added. Modern Acoustics Science and Technology Series: Hydroacoustics (2nd Edition) can be used as a reference for scientific research and teaching workers and graduate students engaged in hydroacoustics, marine physics and geophysics.