These proceedings are a collection of 16 selected scientific papers and reviews by distinguished international experts that were presented at the 4th Pacific Rim Underwater Acoustics Conference (PRUAC), held in Hangzhou, China in October 2013. The topics discussed at the conference include internal wave observation and prediction; environmental uncertainty and coupling to sound propagation; environmental noise and ocean dynamics; dynamic modeling in acoustic fields; acoustic tomography and ocean parameter estimation; time reversal and matched field processing; underwater acoustic localization and communication as well as measurement instrumentations and platforms. These proceedings provide insights into the latest developments in underwater acoustics, promoting the exchange of ideas for the benefit of future research.

Autorentext

Lisheng Zhou received an M.S. degree in Underwater Acoustics Engineering from Harbin Engineering University, Harbin, China, in 1991. Since 1991, he has been at the Hangzhou Applied Acoustics Research Institute (HARRI), Hangzhou, China and currently its director. He has been engaged in the research and development of new underwater acoustic transducer and underwater acoustic systems. He was selected by the "Millions of Talents Project" of China and the first class of "New Century 151 Talents Project" of Zhejiang Province in 1998. He won the "Outstanding Contributions of Young Experts" in 1998. He has received special government funding since 1999. 

Wen Xu received his B.E. in Electrical Engineering from the University of Science and Technology of China, Hefei, China, in 1990, an M.S. in Acoustics from the Institute of Acoustics, Chinese Academy of Sciences, Beijing, China, in 1993, and a Ph.D. in Oceanographic Engineering from the Massachusetts Institute of Technology (MIT), Cambridge, MA, USA, in 2001. From 1993 to 1996, he was a research engineer at the Chinese Academy of Sciences Institute of Acoustics. He was a research scientist in the Ocean Acoustics Group at MIT from 2001 to 2002, and at Teledyne RD Instruments, San Diego, CA, USA, from 2003 to 2007. Currently, he is a professor and the Vice Dean at the College of Information Science and Electronic Engineering, Zhejiang University, Hangzhou, China. He is an associate editor of the IEEE Journal of Oceanic Engineering. His research focuses on statistical and array signal processing in general and in applications in sonar, radar, and communication systems, and most recently in  underwater sensor networks.                                    

Qianliu Cheng received a B.E. in Underwater Acoustics Engineering from Harbin Engineering University, Harbin, China, in 1991. Since 1991, he hasbeen at the Hangzhou Applied Acoustics Research Institute (HARRI), Hangzhou, China and is currently a senior researcher there. His research focuses on statistical and array signal processing applied in sonar. 

Hangfang Zhao received a B.E. in Electrical Engineering from Xidian University, Xi'an, China, in 1991, an M.S. in Underwater Acoustics Engineering from Harbin Engineering University, Harbin, China, in 1997, and a Ph. D. in Communication and Information Systems from Zhejiang University, Hangzhou, China, in 2010. From 1991 to 2012, she worked at the Hangzhou Applied Acoustics Research Institute, Hangzhou, China, where she conducted research into acoustic signal processing and acoustic engineering. Currently, she is a professor at the College of Information Science and Electronic Engineering, Zhejiang University, Hangzhou, China. Her research interests include array signal processing, robust signal processing, sparse approximation and inverse problems, with applications to sonar, radar, and communication systems.

Inhalt
Inference of Sound Attenuation in Marine Sediments from Modal Dispersion in Shallow Water.- Distributed Underwater Sensing: Applications and Challenges.- Counterintuitive Results in Underwater Acoustic Communications.- Comparisons of Methods for Numerical Internal Wave Simulation in Long Range Acoustical Propagation.- Acoustic Data Assimilation: Concepts and Examples.- The Preliminary Results of a Single-Hydrophone Geoacoustic Inversion for Data Collected at the Sea of Japan.- Measurements of Ultrasound Attenuation of Suspended Particles with Various Size Distributions.- A Low Complexity Multichannel Adaptive Turbo Equalizer for a Large Delay Spread Sparse Underwater Acoustic Channel.- A Turbo Equalization Based on a Sparse Doubly Spread Acoustic Channels Estimation.- Design and Testing of Underwater Acoustic Communications for an AUV.- Hydroflown™: MEMS Based Underwater Vector Sensors and Applications.- Axis Mismatches Between Pairs of Sensitive Elements of Underwater Acoustic Velocity Gradient Sensors.- A Passive Fathometer Technique for Bottom Profiling Using Ambient Noise Target Motion Parameter Estimation for LOFARgrams Based on Waveguide Invariants.- Source Localization by Maximizing the Longitudinal Correlation Using Waveguide Invariant Theory.- Selective Detection and Localization by Decomposition of a Subrank Time Reversal Operator.- Sounds of Undersea Gas Leaks.- Multi-AUV Localization for an Underwater Acoustic Sensor Network.