This book provides comprehensive coverage of the detection and processing of signals in underwater acoustics. Background material on active and passive sonar systems, underwater acoustics, and statistical signal processing makes the book a self-contained and valuable resource for graduate students, researchers, and active practitioners alike. Signal detection topics span a range of common signal types including signals of known form such as active sonar or communications signals; signals of unknown form, including passive sonar and narrowband signals; and transient signals such as marine mammal vocalizations. This text, along with its companion volume on beamforming, provides a thorough treatment of underwater acoustic signal processing that speaks to its author's broad experience in the field.

Auteur

Douglas A. Abraham received B.S., M.S., and Ph.D. degrees in electrical engineering and an M.S. degree in statistics from the University of Connecticut, Storrs. He has performed basic and applied research in underwater acoustic signal processing at the Naval Undersea Warfare Center (New London, CT), the NATO SACLANT Undersea Research Centre (La Spezia, Italy), and the Applied Research Laboratory at Pennsylvania State University. He presently continues his professional and technical activities as a consultant. Dr. Abraham has also taught at the University of Connecticut as visiting faculty, and managed basic and applied research programs at the Office of Naval Research through an intergovernmental personnel assignment.

Contenu
Part I Sonar and underwater acoustics
1 Introduction to underwater acoustic signal processing . . . . 31.1 Overview of underwater acoustic signal processing . . . . . . . . . . 31.1.1 Common applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51.1.2 Signal and information processing . . . . . . . . . . . . . . . . . . 61.1.3 Underwater acoustic system and signal processing examples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71.1.4 Development process for novel applications . . . . . . . . . . 71.2 Intended use and organization of this book . . . . . . . . . . . . . . . . 8References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112 Sonar systems and the sonar equation . . . . . . . . . . . . . . . . . . . . 132.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 132.2 Remote sensing with sonar systems . . . . . . . . . . . . . . . . . . . . . . . 132.2.1 Components of a sonar system . . . . . . . . . . . . . . . . . . . . . 142.2.2 Monostatic, bistatic, and distributed sonar systems . . . 162.2.3 Estimating position of a sound or scattering source: localization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 172.2.4 Bistatic active sonar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 242.2.5 Doppler scale and shift . . . . . . . . . . . . . . . . . . . . . . . . . . . . 272.2.6 Doppler sensitive and insensitive waveforms . . . . . . . . . . 332.3 The sonar equation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 342.3.1 Decibel notation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 362.3.2 The basic passive sonar equation . . . . . . . . . . . . . . . . . . 392.3.3 The basic active sonar equation . . . . . . . . . . . . . . . . . . . 452.3.4 Summary of sonar equation terms . . . . . . . . . . . . . . . . . . 512.3.5 Relating SNR to detection performance: Detection Threshold . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 522.3.6 Relating SNR to estimation performance . . . . . . . . . . . . 622.3.7 Other applications of the sonar equation . . . . . . . . . . . . 64References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 693 Underwater acoustics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 713.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 713.2 Acoustic propagation in the ocean . . . . . . . . . . . . . . . . . . . . . . . . 713.2.1 Acoustic pressure, particle velocity, intensity, power, and energy density . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 733.2.2 The wave equation and spherical waves . . . . . . . . . . . . . 773.2.3 Periodic signals, wavelength, and wavenumber . . . . . . . 803.2.4 Cylindrical spreading and plane waves . . . . . . . . . . . . . . 823.2.5 Nearfield and farfield propagation . . . . . . . . . . . . . . . . . . 843.2.6 Inhomogeneous wave equation and the channel impulse response . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 863.2.7 The Helmholtz equation and channel frequency response . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 893.2.8 Source level and transmission loss . . . . . . . . . . . . . . . . . . 903.2.9 Absorption and dispersion . . . . . . . . . . . . . . . . . . . . . . . . . 943.2.10 Sound-speed, Snell's law, and refraction . . . . . . . . . . . . . 953.2.11 Boundaries and reflection loss . . . . . . . . . . . . . . . . . . . . . . 1013.2.12 Rays and modes in shallow water . . . . . . . . . . . . . . . . . . . 1163.2.13 Reciprocity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1243.3 Ambient noise . . . . . . . . . . . . ...