地基雷达一直是空间碎片监测的有力工具,研究如何利用它们对尺寸小于距离分辨率的目标进行成像具有重要意义。基于空间碎片通常会围绕它的主轴进行简单的自旋转运动这一事实,通过对目标回波模型的分析,本文提出了一种基于稀疏信号表示的空间碎片成像方法。该方法将成像问题转化为稀疏信号分解问题,首先以各个散射点的散射特性作为元素构建字典,然后通过采用现有的方法对单个距离单元横向回波数据的稀疏信号表示进行求解,最后对求解的结果重新排列以得到目标的二维高分辨图像。仿真实验结果表明了本方法的正确性。
Ground-based radar is a powerful tool for monitoring space debris.Imaging of the space debris with dimensions smaller than the range resolution is of great significance.Based on the observation that space debris usually follows a simple spin motion around its major axis,a novel method for radar imaging of space debris based on sparse signal representation is proposed by analyzing the signal model of the target.In the proposed method,the imaging problem is converted to the problem of sparse signal decomposition.First,a complete dictionary is constructed by elements which represent the scattering properties of each point.Then,a sparse representation of the single range unit's radar echo is solved by using the exsisting method.Finally,the 2D high resolution image of the target is obtained by rearranging the solved result.Furthermore,the validity of the proposed approach is confirmed by using numerical simulations.