水下脉冲激光探测后向散射噪声自适应滤波算法

An adaptive filter algorithm of underwater pulse laser detection based on backscattering correlative characters

摘要:

在信号处理中抑制水体传输中带来的后向散射噪声，是水下脉冲激光探测的关键技术之一。基于同一水域相邻2次探测后向散射的相关性，提出一种改进的归一化最小均方（NLMS）自适应滤波算法。根据后向散射的强度和滤波后目标信号大小控制步长因子，使其对不同距离、不同强度的目标信号均能取得良好的滤波效果。通过计算机仿真和水池实验对算法进行验证，结果表明，对不同距离、不同反射强度的目标，该滤波器算法均能以较低的阶数有效滤除后向散射噪声，保留目标回波信号。与现有的自适应滤波方法相比，大大减少了滤波所需的计算资源，在水下脉冲激光探测系统上具有一定的应用价值。

Abstract:

It is one of the key technologies of underwater pulsed laser detection to suppress the backscattered noise caused by water transmission in signal processing. Based on the correlation between two adjacent detections of backscattering in the same water area, an improved Normal Least Mean Square(NLMS) adaptive filtering algorithm is proposed. The step factor is controlled according to the intensity of backscattering and the size of the filtered target signal to make it achieve good filtering effect for target signals at different distances and intensities. The algorithm is verified by simulation and swimming pool experiment. The results show that the filter algorithm can effectively filter the backscattered noise with a lower order for targets with different reflection strengths at different distances, and retain the target echo signal. Compared with the existing adaptive filtering method, it greatly reduces the computing resources required for filtering, and has certain application value in underwater pulsed laser detection systems.