强多途环境下水听器阵列位置近场有源校正方法

A geometric calibration mehtod of hydrophone array with known sources in near field under strong multipath

针对水听器阵列近场强多途环境下的校正需求,提出了一种高精度的多辅助源阵列位置校正方法.综合近场点源非平面波模型和泰勒近似原理,构建了近场阵元位置二维误差模型,进而获得信号特征向量与阵元位置误差的线性映射关系.推导并计算了校正模型的克拉美罗界(CRB).研究了多途对阵元位置校正的影响,将多途干扰视为位置已知的相干源,提出了多途补偿策略.理论及仿真结果表明,近场多辅助源阵列位置校正方法具有较高的精度,在低信噪比时接近CRB,对于辅助源位置等误差具有一定的容忍度,且适用于强多途环境.湖试验证了方法结论的正确性.

In order to meet the demand of underwater acoustic array calibration in near field with strong reflection, a high-precision geometric calibration method with known sources is proposed. Colligating the principles of non-plane wave model of point source and the Taylor approximation, a two-dimensional geometry error model for near field is established. And then the line mapping relationship is obtained between geometric error of sensors and signal eigen vector. Cramer-Rao bound （CRB） of this mode is deduced and analyzed. The influence of multipath on geometric calibration is studied. The strong reflections are compared to the coherent sources at a known position, and the compensation strategy is realized. The results from theory and simulation show that the precision of geometry calibration technique with accessorial sources in near field is high and it is close to the CRB in the case of low SNR. The method has a certain tolerance for the position error of accessorial sources. And it is applicable for multipath. Pool test results further verify the correctness of these results.