浅海低频本地海底混响的波导不变性结构及抑制方法研究  

Waveguide invariance structure for low frequency monostatic bottom reverberation mitigation in shallow water

作　　者：郭国强[1] 杨益新[1] 孙超[1] 李博[1] 

机构地区：[1]西北工业大学航海学院,西安710072

出　　处：《声学学报》2009年第6期506-514,共9页Acta Acustica

基　　金：国家自然科学基金(10504026);陕西省自然科学基础研究计划(SJ08A08)资助项目

摘　　要：根据浅海混响的射线简正波相干混响理论和可分离的海底散射模型,从理论上推导了浅海低频本地海底混响信号中存在的稳定的距离-频率干涉结构(波导不变性结构),并在此基础上基于谱相减的思想提出了一种基于波导不变性的本地海底混响预测对消方法。针对某个检测距离,其对应的中心频率上的海底混响强度可以根据波导不变性通过频移的方法在另一个与之相邻的距离上估计得到,利用该估计的混响强度可以对消检测距离对应的回波信号中的海底混响强度分量,增强回波信混比,提高目标检测能力。针对典型水平分层浅海波导环境,通过计算机仿真实验分析了低频海底混响存在的稳定波导不变性结构,验证了本文提出的基于波导不变性的混响预测对消方法的有效性。The stable range-frequency interference structure （waveguide invariance） for low frequency monostatic bottom reverberation in shallow water is derived theoretically in this paper by using ray-normal mode coherent reverberation model combined with separable bottom scattering model. And a reverberation forecasting and mitigating method based on the waveguide invariance is presented. According to the waveguide invariance, the reverberation intensity for the detecting range can be estimated from the reverberation signals for other ranges with frequency shift. Then the re- verberation component for the detecting range can be canceled mostly in the echo intensity, so as to enhance the echo-to-reverberation ratio and improve the detection capability of the active sonar. Simulations in typical horizontal layered shallow water environment showed the stability of waveguide invariance structure in the low frequency monostatic bottom reverberation and the efficiency of the reverberation forecasting and mitigating method based on the waveguide invariance.

关 键 词：海底混响 浅海混响 波导 变性 结构 抑制方法 低频 检测距离 

分 类 号：P733.2[天文地球—物理海洋学]