空间目标距离像畸变分析及运动参数估计  

Distortion Analysis on High Resolution Range Profile of Space Target and Motion Parameter Estimation

作　　者：杜小勇[1] 张乐锋[1] 胡卫东[1] 

机构地区：[1]国防科学技术大学自动目标识别重点实验室,长沙410073

出　　处：《中国空间科学技术》2014年第3期1-7,共7页Chinese Space Science and Technology

基　　金：国家自然科学基金(61002021)资助项目

摘　　要：针对卫星目标的宽带雷达回波信号,从理论上详细分析了目标运动产生的多项式相位模型,指出三次以上的相位对一维距离像的畸变可以忽略。以频谱主瓣的展宽程度为判据,推导了二次相位需补偿时的目标速度边界条件。结果表明,在典型参数条件下卫星目标的径向速度远大于该临界速度(约560m/s),需在成像前予以补偿。最后,结合雷达目标散射中心的稀疏分布特性,提出了基于L1范数的空间目标运动参数估计算法。结果表明,该算法对速度的估计误差接近克拉美-罗下界,且远小于临界速度,可用于卫星目标成像。Aiming at the wideband radar echo signal returned from the satellite,the polynomial phase model was analyzed in detail due to its high speed motion.As a result,the distortion on high resolution range profile caused by three or higher degree polynomial can be neglected.According to the width of spectrum mainlobe at different velocities,a bound condition was derived to compensate the quadratic phase.The result indicates that the satellite speed is much greater than the derived bound （near 560 m/s） with the typical operating parameters,and should be compensated before imaging.Furthermore,based on the sparse distribution characteristics of scattering centers,an L1-norm based algorithm was presented to estimate the satellite velocity.Simulations show that the standard deviation of the estimator is close to the Cramer-Rao lower bound,and the estimation error is much less than the derived bound for compensation.The proposed algorithm is applicable for satellite imaging.

关 键 词：雷达成像 运动参数估计 L1范数 空间监视 卫星目标 

分 类 号：TN959.17[电子电信—信号与信息处理]