基于激光偏振特性的水下声信号探测方法研究

Underwater Acoustic Signal Detecting with the Method of Laser Polarization

水下航行体辐射的声波传播到水-空气分界面上时,会在水表面形成微扰,使水表面元产生微倾角。提出一种利用激光偏振特性对水下声信号进行探测的方法,不直接利用散射光强信息,而是利用激光在布儒斯特角附近入射水表面时,反射光偏振特性随入射角剧烈变化的特点对水表面微扰进行高精度探测。建立了该方法的理论模型,得到了入射波、出射波垂直分量与平行分量的功率比P_A、P_R与入射角θ_i之间的关系。通过分析发现,当光源为自然偏振状态时,该方法无需对妑P_A进行测量就可以通过测量P_R而直接计算出水面入射角θ_i,进而实现对水下声信号的探测。仿真结果表明,该检测方法测量精度高,抗干扰能力强。

The water surface perturbations generated by underwater acoustic signal form submarine ship result in slight change of water surface obliquity. A kind of new method is presented, which can extract underwater acoustic signals by laser polarization characteristic. The used information isn ＇t scattered light intensity directly, but the tempestuously change of reflected laser polarization state with the angle of incidence when the angle of incidence is near the Brewster angle. This technique is used for precision measure for water surface perturbations generated by underwater acoustic signal. Underwater acoustic signals detection academic model by laser polarization characteristic is built and the relations of PA （incident light＇s power rate of vertical component and parallel component） and PR （reflected light＇s power rate of vertical component and parallel component） with the angle of incidence Oi respectively is analyzed. In parti culated by measuring PR directly and the detection of underwater acoustic signal polarization state. There is no need to measure Pa to this method. The results nique has higher measure precision and stronger anti jamming ability. eular, the angle of incident light θ＇ can be calcan be achieved if the incident light is natural suggest that the detection based on this technique has higher measure precision and stronger anti jamming ability.