水下激光告警器信噪比分析计算及仿真

Analysis calculation and simulation on signal to noise ratio for underwater laser alarm

在反猎雷预警系统中,激光告警设备主要用来识别敌对激光信号的方位。水体对激光衰减使告警器性能降低,对光的吸收使接收器信噪比降低,散射使定向精度变低。使用传输方程理论建立了激光在水下传输模型,运用傅里叶变换及平面波扩展方法求解水体传输方程。利用光的互易原理及传输方程得到了探测器平面上的二维空间光强分布模型。仿真计算了探测器在清洁海水、近岸海水、浑浊海水等海水环境时直射光与散射光的响应。仿真实验结果表明所提出的方法可用于评估水下告警系统探测器接收性能。

In anti-hunting early warning system, laser warning equipment was mainly used to identify the orientation of enemy laser signal. Water＇s laser attenuation nature would reduce performances of alarm, its light absorption nature would lower SNR of the receiver and its scattering character would reduce the orientation precision. Firstly, transmission equation theory was used to establish underwater transmission model of laser and then Fourier transform and plane wave expansion method were used to solve water transport equation. Lastly, light reciprocity principle and transmission equation were utilized to obtain the two-dimensional spatial intensity distribution model of the probe in the plane. Simulation had been used to calculate the response of detector to direct light and scattered light at different seawater environment in clean water, coastal water and turbid water. Results of the simulation show that the proposed method in this paper could be used to assess receptivity performance of the detector in underwater alarm system.