针对星载雷达空间碎片群目标回波无法分离问题,该文利用回波在距离向表现出的块聚集特性,提出一种基于块稀疏的高分辨ISAR成像方法。基于块稀疏压缩感知理论,通过利用空间碎片群目标特性,抽取出各个碎片的高分辨1维距离像数据,并结合平动补偿和距离多普勒(RD)算法得到各碎片的ISAR像。在小样本条件下,该方法能够有效实现空间碎片的数据分离和高分辨ISAR成像。仿真实验表明,该方法的重构精度以及运算速度均优于非结构类的稀疏ISAR成像方法。
Space debris often appears in the form of groups, and the radar echoes overlap each other along the range direction. Utilizing the block structure, a high resolution space debris imaging method of ISAR is proposed based on the block-sparse Compressed Sensing (CS). This method can get high resolution 1-D range profile of every debris based on the block-sparse CS with the characteristics of space debris, and obtain the ISAR image combined with the translation compensation and the Range Doppler (RD) algorithm. The simulation results illustrate that the proposed method can achieve high resolution ISAR image with less reconstruction error and iterative number compared with the non-structure CS method under limited measurements.