用时间反转法在水下波导介质中实现自适应聚焦的研究

Study of self-focusing in underwater waveguide by time reversal method

研究了水下波导中声波时间反转自适应聚焦问题,分别在半无界流体介质和置于半无界刚性固体之上的流体层中开展了时间反转法的理论和实验研究工作。理论上采用射线近似方法分析了时间反转声场特性,实验上在实验室内开展了水下波导的超声模拟实验。理论和实验证明,聚焦增益可以提高 12 dB以上。

Acoustic wave time reversal self-focusing in underwater waveguide is studied. The acoustic wave time reversal is theoretically and experimentally investigated in a half-infinite fluid medium and a shallow fluid layer placed on a hard half-infinite solid medium, respectively. The ray approach is adopted to study the acoustic field in theory, and the ultrasonic experiment has been carried out in laboratory to model the underwater waveguide. It is showed by theoretical and experimental studies that the focusing gain can be improved to more than 12 dB.