复杂海洋环境噪声下甚低频声信号检测方法

针对复杂海洋环境中的探测潜艇目标问题，开展复杂海洋环境噪声下的甚低频信号检测研究。采取更加符合实际的列维分布描述复杂海洋低频环境噪声，并基于对数矩法估计实测噪声的分布参数，为后续的系统参数选取提供先验知识；提出随机共振来检测复杂海洋环境噪声下的甚低频信号，分析列维噪声下的2阶随机共振方法；推导列维噪声下随机共振系统匹配参数，建立2阶双稳态匹配随机共振信号检测系统。仿真实验结果表明：2阶匹配随机共振检测器比传统相关检测器的检测性能优越很多；在虚警概率0.01条件下要使得检测概率达到0.9，比相关检测器所需输入信噪比降低10 dB. 通过外场湖中试验，验证了该系统对水下移动航行器产生甚低频声信号的有效检测。

Detection Method of VLF Acoustic Signal in Complex Marine Environmental Noise

The detection of very low frequency (VLF) signal in the complex marine environment is studied to detect the submarine targets in the complex marine environment. The Lévy distribution is used to describe the noise in complex marine low-frequency environment, and the logarithmic moment method is used to estimate the distribution parameters of the measured noise. A priori knowledge is provided for the following system parameter selection. And then a stochastic resonance method is proposed to detect the very low-frequency signal in the complex marine environmental noise, and the second-order stochastic resonance method under the Lévy noise is analyzed. The matching parameters of stochastic resonance system under Lévy noise are derived, and a detection system of second-order bistable matching stochastic resonance is established. The simulated results show that the detection performance of the second-order matched stochastic resonance detector is much better than that of the traditional correlation detector. When the false alarm probability is 0.01, the detection probability can reach 0.9. Compared with the correlation detector, the required input signal-to-noise ratio can be reduced by 10 dB. Through the field lake experiment, it was verified that the system can effectively detect the VLF sound signals generated by underwater mobile vehicle.