Symmetry Properties of Acoustic Fields-Time Reversal Symmetry, Reciprocity Theorem -- Time Reversal Acoustics-Helmholtz Wave Equation has both Right Travelling and Left Travelling Wave Solutions -- Time Reversal gives rise to Superresolution -- Application to Nondestructive Evaluation - Experimental Setup and Case Studies -- Application to Medical Ultrasound Imaging -- Application to Underwater Acoustics -- Time Reversal Acoustics and Underwater Communication Technology -- Time Reversal Acoustics and Metamaterials -- Signal Processing -- Conclusions.

This book highlights time reversal acoustics, techniques based on the symmetry properties of acoustic fields. It has the unique feature that the first eleven chapters of the book are on the indepth studies of the theories of time reversal acoustics. The remaining chapters are on the four major applications of time reversal acoustics, together with their experimental setups and case studies: underwater communication, seismic exploration,nondestructive evaluation, and medical ultrasound imaging.. The gauge invariance approach to acoustic fields, proposed by the author in 2007, is confirmed by the successful fabrication of acoustical metamaterials and the applications of time reversal acoustics to superresolution. The book also presents groundbreaking applications of time reversal acoustics to underwater communication technology and the application of metamaterials to time reversal acoustics.