超宽带SAR子孔径NCS实时成像算法  

A New Subaperture Nonlinear Chirp Scaling Algorithm for Real-Time UWB-SAR Imaging

作　　者：王建[1] 薛国义[1] 周智敏[1] 宋千[1] 

机构地区：[1]国防科技大学电子科学与工程学院,湖南长沙410073

出　　处：《信号处理》2008年第3期390-394,共5页Journal of Signal Processing

基　　金：2005航天支撑技术基金资助

摘　　要：本文提出了一种适用于超宽带SAR实时成像的子孔径非线性CS(Nonlinear Chirp Scaling)算法,该算法利用方位向信号分量的时间和频率的锁定关系,在时域中互不重叠地划分子孔径,大大降低了系统存储量和运算量的需求,并采用时域加权方法将非重叠子孔径划分造成的假目标抑制到-31dB;此外,将MD自聚焦技术融入子孔径结构中,实现对大孔径复杂运动误差的有效补偿。仿真数据和实际数据验证了该算法的有效性。This paper presents a subaperture Nonlinear Chirp Scaling （NCS） algorithm for real-time Ultra-Wide Band SAR （UWB-SAR） imaging. Based on one-to-one correspondence of frequency and time, the nonoverlapped subapertures are formed in the time domain at the beginning of the process. The nonoverlapped subapertures result in a decrease in memory requirement and computational load, and result in a pair of ghosts. Fortunately, we suggest a window weighting technique which depresses the paired ghosts to -31dB. Beside this ,the MapDrift autofocus technique is incorporated to compensate the complex motion error along the large aperture. The vitality of the algorithm is demonstrated by simulation and real UWB-SAR image formation.

关 键 词：超宽带SAR 子孔径 NCS算法 运动补偿 

分 类 号：TN958[电子电信—信号与信息处理] TB302.5[电子电信—信息与通信工程]