浅海波导中简正波干涉特征频率增强

针对浅海波导中水平线列阵接收的低频宽带低信噪比信号，提出了一种利用多拍信号相干累加来提高干涉简正波特征频谱信噪比的方法。这种方法主要针对未知距离和声源形式的运动声源，对不同时刻（或接收距离）处阵列输出信号进行WARPING变换，基于干涉简正波特征频率不变性原理，通过距离和径向速度比值的搜索来使得不同时刻或距离处信号自相关函数WARPING变换后频谱具有近似相同的特征频率，进而通过相干累加来增强信号干涉简正波特征频率。仿真和海上实验数据分析均验证了方法的性能。

Enhancement of frequency characteristics of interference normal mode pairs in shallow water waveguides

Aiming at the low-frequency and low signal-to-noise ratio signals received by a horizontal line array in shallow-water waveguides, an approach to enhance the signal-to-noise ratio of characteristic spectra of the interference normal mode pairs was proposed based on coherent accumulation of multiple snapshot signals. For a moving sound source without knowledge of range and waveform, WARPING transform is performed on the array output signals at different time or receiving ranges. Based on the invaribility of the characteristic frequency of the interference normal modes pairs, the WARPING transform spectra of auto-correlation functions of the signals at different time or ranges are matched for approximately equal characteristic frequencies through searching the ratio of range and radial velocity. And then, coherent accumulation is used to enhance the features of the characteristic frequencies of the interference normal modes pairs. The simulation and the analysis of marine experimental data verify the performance of the approach.