GSC结构相控阵在主瓣干扰下的自适应单脉冲方法

Adaptive monopulse approach under mainlobe jamming of phased array based on GSC

当有源干扰从旁瓣进入广义旁瓣对消器(general sidelobe canceller,GSC)结构相控阵系统时,通过对旁瓣干扰的抑制,可以维持较高的单脉冲测角精度,然而当干扰进入主瓣范围内时,自适应方向图会发生畸变,导致测角错误。针对这一问题,提出了一种在GSC结构下的两级自适应单脉冲测角的工程实现方法,首先对采样协方差矩阵进行特征分解并根据主瓣子空间的正交性分离主瓣干扰对应的特征向量,由此重构旁瓣干扰和噪声协方差矩阵,再利用旁瓣对消器抑制旁瓣干扰,最后通过四通道系统抑制主瓣干扰并保持单脉冲比不变,实现对目标的精确测角。该方法无需对干扰的来波方向进行预估计,具有较强的鲁棒性,仿真结果验证了该方法的有效性。

When the sidelobe jamming enters the phased array based on general sidelobe canceller(general sidelobe canceller,GSC)structure,high accuracy of monopulse angle estimation can be maintained by suppressing the sidelobe jamming,but if the interference enters from the mainlobe,the adaptive pattern will be distorted,which resulting in angle measurement errors.Aiming at this problem,an engineering realization method of two-stage adaptive monopulse angle measurement under the GSC structure is proposed.Firstly,the sampling covariance matrix is eigen-decomposed and the eigenvectors corresponding to the mainlobe jamming are separated according to the orthogonality of the mainlobe subspace,which can be used to reconstruct the sidelobe jamming and noise covariance matrix.Then,the sidelobe canceller is used to suppress the sidelobe jamming.Finally,the four-channel system is used to suppress the mainlobe jamming and maintain the monopulse ratio,which can achieve accurate angle measurement of the target.This method doesn’t need to pre-estimating the jamming direction,which has stronger robustness.The simulation results demonstrate the effectiveness of the propose method.