扫描雷达未知天线方向图误差下的稀疏目标角超分辨重建方法

Sparse Targets Angular Super-resolution Reconstruction Method under Unknown Antenna Pattern Errors for Scanning Radar

扫描雷达角超分辨技术是基于目标与天线方向图的关系,采用解卷积方法获取超越实波束的角分辨能力。目前的角超分辨方法大都是基于理想的无畸变天线方向图,未考虑实际过程中方向图的变化。然而,由于雷达天线罩、天线测量误差与平台非理想运动等因素的影响,天线方向图在实际中往往存在未知的误差,会导致目标分辨能力下降,甚至产生虚假目标。针对此问题,该文提出一种机载扫描雷达未知天线方向图误差下的角超分辨成像方法。首先,基于总体最小二乘(TLS)准则,该文考虑了方向图误差矩阵的影响,导出了相应的目标函数;其次,基于交替迭代的求解思路,利用迭代重加权优化方法实现了目标函数求解;最后,针对算法超参数选取,引入了一种自适应参数选取方法。仿真与实测结果表明,该文方法能实现未知天线误差条件下的超分辨重建,进一步提升了超分辨算法的稳健性。

Scanning radar angular super-resolution technology is based on the relationship between the target and antenna pattern,and a deconvolution method is used to obtain angular resolution capabilities beyond the real beam.Most current angular super-resolution methods are based on ideal distortion-free antenna patterns and do not consider pattern changes in the actual process due to the influence of factors such as radar radome,antenna measurement errors,and non-ideal platform motion.In practice,an antenna pattern often has unknown errors,which can result in reduced target resolution and even false target generation.To address this problem,this paper proposes an angular super-resolution imaging method for airborne radar with unknown antenna errors.First,based on the Total Least Square(TLS)criterion,this paper considers the effect of the pattern error matrix and derive the corresponding objective function.Second,this paper employs the iterative reweighted optimization method to solve the objective function by adopting an alternative iteration solution idea.Finally,an adaptive parameter update method is introduced for algorithm hyperparameter selection.The simulation and experimental results demonstrate that the proposed method can achieve super-resolution reconstruction even in the presence of unknown antenna errors,promoting the robustness of the super-resolution algorithm.