天基ISAR对空间轨道目标高分辨率成像问题分析  

Analysis of high resolution imaging for space orbit targets by space-borne ISAR

作　　者：刘一飞 禹卫东 杨升辉 李世强 LIU Yifei;YU Weidong;YANG Shenghui;LI Shiqiang(Aerospace Information Research Institute,Chinese Academy of Sciences,Beijing 100190,China;School of Electronic,Electrical and Communication Engineering,University of Chinese Academy of Sciences,Beijing 100039,China)

机构地区：[1]中国科学院空天信息创新研究院,北京100190 [2]中国科学院大学电子电气与通信工程学院,北京100039

出　　处：《系统工程与电子技术》2024年第11期3671-3683,共13页Systems Engineering and Electronics

基　　金：2019第四批万人计划(Y9G0100BF0)资助课题。

摘　　要：对空间轨道目标高分辨率成像是空间态势感知计划的重要组成部分。本文讨论天基逆合成孔径雷达(inverse synthetic aperture radar,ISAR)对空间目标进行高分辨率成像的概念。基于雷达和空间轨道目标相对运动场景,研究减少天基ISAR回波数据量的方法;分析天基ISAR对空间目标可成像时间段的限制因素,推导天基ISAR与目标轨道高度差及天基ISAR波束扫描角度的噪声等效后向散射系数(noise equivalent sigma zero,NESZ)公式,探讨满足方位分辨率的天基ISAR在轨可成像时间段,并利用NESZ衡量可成像时刻内回波信噪比(signal to noise ratio,SNR),为天基ISAR系统设计提供依据。此外,还推导天基ISAR对空间轨道目标回波表达式,并研究二维图像散焦原因,提出ISAR图像二维相位误差具体补偿模型,通过仿真结果验证了分析的正确性。Achieving high-resolution imaging of space orbit targets,which constitutes a crucial component of space situational awareness programs.The concept of space-borne inverse synthetic aperture radar(ISAR)for achieving high-resolution imaging of space targets is discussed in this paper.Methods to reduce the amount of space-borne ISAR echo data are studied based on the relative motion between radar and space orbit targets.The limiting factors affecting the imaging time period of space-borne ISAR on space targets are analyed,and formulas for noise equivalent sigma zero(NESZ)are derived considering the height difference between the target’s orbit and the scanning angle of space-borne ISAR beams.The study explores the achievable imaging time window for azimuth resolution by using NESZ to measure the signal to noise ratio(SNR)of the echoes within the imaging time window,thereby providing guidance for the design of space-borne ISAR systems.Furthermore,this paper derives the expression of the echoes from space orbit targets for space-borne ISAR and investigates the causes of two-dimensional image defocusing.A specific compensation model for the two-dimensional phase error in ISAR images is proposed,and the correctness of the analysis is verified through simulation results.

关 键 词：天基逆合成孔径雷达 空间轨道目标 高分辨率成像 

分 类 号：TN958[电子电信—信号与信息处理]