基于波导不变量的单水平阵被动测距技术

Passive ranging with horizontal array based on waveguide invariant

浅海低频声场具有稳定的干涉特性,水听器接收信号声强图中的干涉条纹包含了目标的运动和距离信息。在推导水平直线阵波束域信号声强表达式的基础上,提出一种可用于单水平直线阵的运动目标被动测距技术。该技术利用波导不变量理论并结合水平阵转向前后的波束域声强信息实现目标的被动测距。在使用Hough变换进行运动参数的估计之前,采用对比度拉伸变换和中值滤波的图像预处理方法,以提高低信噪比条件下参数估计的准确性和稳健性。理论分析和仿真研究结果表明,所提算法能够有效地对运动目标进行被动测距,对目标是否通过最近距离点没有限制,具有更广泛的适用性。

There exist stable interference striations in the intensity plot of shallow water low frequency acoustic field, which contain target＇s motion,and range information. The beam intensity expression of a horizontal array receiving signal is derived. A moving target passive ranging technique with a horizontal line array is proposed. The waveguide invariant theory and the horizontal array beam intensity before and after it changes course during the motion are used for target＇s passive ranging. Before estimating parameters through Hough transformation, image processing methods including contrast stretching transformation and median filtering are used to improve the accuracy and robustness of the parameter estimation＇ in low signal-to-noise ratio environment. Theoretical analysis and simulation results show that the moving target＇ s range can be estimated effectively by using the algorithm proposed. There is no restriction on whether the target moves through the closest range, it is more applicable.