基于时频分析的雷达非匀速运动目标参数估计  

Parameter estimation for radar non-uniform moving target based on time-frequency analysis

作　　者：杨磊 雷梦尧 YANG Lei;LEI Mengyao(College of Electronic Information and Automation,CAUC,Tianjin 300300,China)

机构地区：[1]中国民航大学电子信息与自动化学院,天津300300

出　　处：《中国民航大学学报》2023年第4期29-36,共8页Journal of Civil Aviation University of China

基　　金：国家自然科学基金项目(62271487)。

摘　　要：针对合成孔径雷达(SAR,synthetic aperture radar)地面非匀速运动目标参数估计问题,提出了基于吕分布(LVD,Lv′s distribution)的自适应陷波器(ANF,adaptive notch filter)方法。首先,根据地面非匀速车辆目标运动情况建立雷达回波数学模型,并分析推导了回波信号多普勒参数和运动参数的理论公式;其次,利用伪魏格纳分布(PWVD,pseudo Wigner-Ville distribution)算法提取回波信号中由高阶运动引起的高阶相位,通过多项式拟合方法进行补偿,并对运动补偿后的动目标信号沿方位向进行孔径分割,对各个子孔径数据块分别进行基于吕分布算法时频表示,估计得到多普勒调频率值的变化曲线;再利用自适应陷波滤波器对调频率信号中由运动目标的径向加速度引起的高频分量和由航向速度引起的低频分量进行精确分离;最后,对提取的调频率高低频分量进行反演计算,得到非匀速运动目标的径向加速度和航向速度估计值。将本文所提方法与基于吕分布低通滤波器方法进行对比实验,验证本文所提方法在运动参数估计方面取得了更高精度。For the parameter estimation of ground non-uniform moving targets of synthetic aperture radar(SAR),an adaptive notch filter(ANF)method based on Lv′s distribution(LVD)is proposed.Firstly,the mathematical model of radar echo is established according to the movement of ground non-uniform vehicle target,and the theoretical formulae of Doppler parameters and motion parameters of the echo signal are analyzed and deduced.Secondly,the pseudo Wigner-Ville distribution(PWVD)algorithm is used to extract the higher-order phase caused by higher-order motion in the echo signal,and the polynomial fitting method is applied to compensate.The motion compensated moving target signal is then aperture segmented along the azimuth direction,and each data block of sub aperture is time-frequency represented based on LVD algorithm,to estimate the variation curve of Doppler modulation frequency value.By utilizing the ANF,the high-frequency components caused by the radial acceleration of the moving target and the low-frequency components caused by the heading velocity in the modulation frequency signal are accurately separated.Finally,inversion calculation of the extracted high-frequency and low-frequency components of the modulation frequency rate are performed to obtain the estimated radial acceleration and heading velocity of non-uniform moving targets.Comparative experiments are conducted between the method proposed in this paper and the low-pass filter method based on LVD to verify that the proposed method can achieve higher accuracy in motion parameter estimation.

关 键 词：雷达 伪魏格纳分布(PWVD) 吕分布(LVD) 自适应陷波器(ANF) 运动参数估计 

分 类 号：TN953[电子电信—信号与信息处理]