浅海大孔径水平阵列频移补偿定位方法

Frequency-shift compensation localization method for large aperture horizontal array in shallow water

浅海波导中简正波干涉使得声场水平相关随距离出现振荡,利用声信号水平距离-频率干涉规律推导了不同阵元接收信号间的频移补偿关系式,结合大孔径阵列阵元空间分布离散度高的特点提出适用于声源频谱缓变信号的定位方法。利用频移补偿量随声源位置的变化,将两两阵元组合输出的模糊度平面叠加实现水平二维平面定位。仿真结果表明方法定位性能良好,对环境参数失配宽容性好。频移补偿后的线性相位关系有效提高了接收信号间的相关性,进而提升大孔径阵列的处理增益。阵列的孔径优势提高了空间分辨能力,模糊度平面峰值-背景比高。海试数据验证表明,10~80 km测距结果平均相对偏差为5.68%,二维平面内定位结果平均距离偏差为0.78 km。

The interference of different normal mode makes the horizontal longitudinal correlation of sound field oscillate.The frequency-shift compensation relationship between the received signals at different positions is derived by using the horizontal distance-frequency interference structure,combined with the characteristics of high dispersion of spatial distribution of large aperture array elements,a localization method suitable for slowly varying spectrum signal is proposed.By using the change of the frequencyshift compensation with the position of sound source,the ambiguity plane of two elements is superimposed to realize the horizontal two-dimensional plane localization.The simulation results show that the method has good localization performance and good tolerance to environmental parameter mismatch.The linear phase relationship after frequency-shift compensation effectively improves the correlation between the received signals,thereby improving the processing gain of the large aperture array.The aperture advantage of the array improves the spatial resolution,and the peak-to-background ratio of the ambiguity plane is high.Sea trial data validation shows that the average relative deviation of 10−80 km ranging results is 5.68%and the average distance deviation of localization results in two-dimensional plane is 0.78 km.