基于空时级联滤波的拖船自噪声抵消方法

Tow-ship noise cancelling based on space-time cascade filtering algorithm

拖船自噪声属于近场多途强干扰信号,具有显著角度扩展现象,是影响拖曳阵探测性能的重要因素之一。在逆波束形成自噪声抵消方法基础上,结合空域和时域滤波,提出了空时级联滤波的拖船自噪声抵消方法。首先,由方位估计器估计拖船自噪声方位,经过波束形成空域滤波估计得到自噪声信号;然后,利用自噪声空域滤波输出设计最优维纳滤波器,将自噪声抵消在阵元级。基于简正波声场模型的仿真和实际海试数据的处理表明,该方法能够有效抵消拖船自噪声,性能优于逆波束形成方法。

For the towed array sonar,the tow-ship noise is a strong interference with a multipath feature.It is one of the important factors that limit the performance of the towed array sonar.Based on the inverse beamforming（IBF） method,and combining the spatial filtering and temporal filtering method,a novel towship noise cancelling method referred to as space-time cascade filtering method was proposed.First,based on the bearing of the tow-ship noise provided by direction-of-arrival（DOA） estimator,the tow-ship noise was estimated by conventional beamforming（CBF） which is a method of spatial filtering.Then,the optimal Wiener filter was designed based on the output of the spatial filtering,and the tow-ship noise was finally cancelled by the noise canceller using Wiener filter.The results of computer simulations based on NormalMode model and real trial data indicated that the proposed method had a better performance than IBF method.