天基逆合成孔径雷达脉内脉间运动补偿及高分辨成像  

Intra-pulse and Inter-pulse Motion Compensation for High-resolution Space-borne Inverse Synthetic Aperture Radar Imaging

作　　者：江利中 罗怡宁 张邦杰 徐刚[3] 肖磊 JIANG Lizhong;LUO Yining;ZHANG Bangjie;XU Gang;XIAO Lei(School of Artificial Intelligence and Automation,Huazhong University of Science and Technology,Wuhan 430074,Hubei,China;Shanghai Radio Equipment Research Institute,Shanghai 200090,China;State Key Laboratory of Millimeter Waves,Southeast University,Nanjing 210096,Jiangsu,China)

机构地区：[1]华中科技大学人工智能与自动化学院,湖北武汉430074 [2]上海无线电设备研究所,上海200090 [3]东南大学毫米波全国重点实验室,江苏南京210096

出　　处：《上海航天（中英文）》2024年第3期176-186,共11页Aerospace Shanghai（Chinese&English）

基　　金：国家自然科学基金(62071113)。

摘　　要：近年来,太空态势感知在军用和民用领域都得到了越来越多的关注。天基逆合成孔径雷达(SBISAR)能够实现对空间目标的高分辨成像,支撑部件提取、姿态估计、类型识别等后续任务,是太空态势感知的重要工具。然而,在SBISAR成像场景下,平台与空间机动目标间存在复杂的相对高速运动,传统距离-多普勒成像方法不再适用,必须进行运动补偿。本文针对高速径向速度下传统“停—走—停”模型失效、长相干积累时间内目标转速不一致的两个典型误差来源,分别设计了脉内运动及脉间运动补偿算法。首先,建立SBISAR成像的信号模型。然后,基于最小熵准则构建参数估计代价函数,通过估计目标对应回波信号的调频率,构造补偿项进而实现脉内补偿。同时,建立图像熵代价函数,在估计转动参数后,完成对目标转动的空变相位补偿。所提算法有效解决了天基高速机动背景下传统距离-多普勒成像方法的距离像展宽、方位散焦问题,实现了SBISAR对空间目标的高分辨成像。通过基于仿真数据的实验分析,验证了所提算法的有效性。In recent years,space situation awareness has garnered increasing attention in both military and civilian fields.Space-borne inverse synthetic aperture radar(SBISAR)is an important tool for space situational awareness.It enables high-resolution imaging of space targets,and supports subsequent tasks such as component extraction,posture estimation,and type identification.However,in SBISAR imaging scenarios,complex and non-uniform high-speed relative motion exists between the platform and the space maneuvering targets,rendering traditional range-Doppler(RD)imaging methods ineffective.Therefore,motion compensation should be considered.In this paper,two typical motion errors are discussed,i.e.,the failure of the traditional“stop-go-stop”model under high radial velocities and the inconsistent target rotation speeds within long coherent processing intervals(CPIs),and a specific algorithm is designed for intra-pulse and inter-pulse motion compensation.First,a signal model for SBISAR imaging is established.Then,based on the minimum entropy criterion,a parameter estimation cost function is constructed to estimate the chirp rate of the echo signal,and the obtained estimation is used to construct a compensation term for intra-pulse motion compensation.Similarly,an image entropy cost function is established to estimate the rotational parameters,achieving spatial-variant phase compensation for rotational motion.The proposed algorithm can effectively address the range extension and azimuth defocusing issues by traditional RD imaging algorithms in the case of high-speed maneuvering,and enables the high-resolution imaging of space targets by SBISAR.Through the experimental analysis based on the simulation data,the effectiveness of the proposed algorithm is validated.

关 键 词：天基逆合成孔径雷达(SBISAR) 脉内运动 机动目标 运动补偿 最小熵 

分 类 号：TN958.2[电子电信—信号与信息处理]