浅海波导中时间反转处理增强信混比能力的仿真分析

针对典型的浅海波导环境,通过计算机仿真研究了目标位于波导中间深度条件下时间反转处理增强信混比的能力以及目标深度的变化对信混比增强能力的影响。对时间反转处理和一般均匀传输产生的目标回波和海底混响强度进行了定量比较。结果表明,在仿真条件下,目标位于波导中间深度时,与一般的均匀传输相比,时间反转处理获得的目标照射强度高10dB～15dB,而相应的海底混响却低了10dB左右,这验证了时间反转处理有效增强信混比的能力,而目标靠近海面或海底时,时间反转处理的海底混响抑制能力有所减弱,当目标位于海底时,由于时间反转聚焦,该距离上将出现一个海底混响峰值。

Echo-to-reverberation enhancement capability of time reversal processing in shallow water

Time reversal processing can focuse acoustic energy on target in shallow water. This self-foc-using enhances target echo while reduces reverberation from the boundaries,resulting in echo-to-reverber-ation enhancement. The capability of time reversal processing for echo-to-reverberation enhancement is st-udied using computer simulation under the condition that target is in the middle of the shallow water guide. Intensity of target echo and the bottom reverberation produced by time reversal processing and broadside transmission are compared numerically. As a result,the energy level emitted to the target by time reveal process is 10-15dB higher than broadside transmission in the simulation,while relevant reverberation level is about 10dB lower,validating the efficiency of time reversal processing for echo-to-reverberation enhanc-ement. Further the effect of target position on the echo to reverberation enhancement is studied,and the simulation result is consistent with theory analysis.