利用HAF-LVD特性的复杂运动目标ISAR成像算法  

ISAR imaging algorithm for targets with the complex motion based on the high-order ambiguity function-Lv's distribution

作　　者：吕倩[1] 苏涛[1] 吴凯[1] 章建成[1] LU Qian SU Tao WU Kai ZHANG Jiancheng(National Key Lab. of Radar Signal Processing, Xidian Univ., Xi＇an 710071, China)

机构地区：[1]西安电子科技大学雷达信号处理国家重点实验室,陕西西安710071

出　　处：《西安电子科技大学学报》2016年第5期24-30,共7页Journal of Xidian University

基　　金：国家自然科学基金资助项目(61271024;61201283);新世纪优秀人才支持计划资助项目(NCET-09-0630)

摘　　要：在复杂运动目标的逆合成孔径雷达成像中,由于转动矢量的时变会产生方位向的高阶相位项,导致方位成像的严重散焦,传统的距离-多普勒算法和线性调频模型已不再适用.因此,在建立逆合成孔径雷达成像回波信号为立方相位信号形式的基础上,提出了利用高阶模糊函数-吕氏分布特性的逆合成孔径雷达成像算法.首先,根据高阶模糊函数和吕氏分布思想定义了双延时参数化瞬时自相关函数,并利用变尺度操作去除耦合及快速傅里叶变换实现信号能量积累.然后,利用得到的高阶模糊函数-吕氏分布完成运动参数的非搜索估计和目标逆合成孔径雷达成像.由于引入可调整的缩放因子,该算法能够在保证成像质量和运算效率的基础上,有效避免谱模糊,灵活应对更加多变和恶劣的成像环境.仿真结果验证了该算法的有效性.In ISAR imaging for targets with the complex motion, since the azimuth high order phase terms caused by the time-varying rotation vector will deteriorate the azimuth focusing quality, the traditional RD algorithm and LFM model are not appropriate. Thereby, in the case when the received signal can be modeled as cubic phase signals （CPSs）, this paper proposes an ISAR imaging algorithm based on HAF- LVD （high-order ambiguity function-Lv＇s distribution）. First, this algorithm defines a novel double lag parametric instantaneous autocorrelation function, and then applies the scaling operator to remove the coupling and utilizes FFT to achieve the energy accumulation. Finally, the non-searching estimation of the moving parameter and the ISAR images for targets are accomplished by the obtained HAF-LVD. Because of the introduction of the scaling factor, this algorithm can flexibly deal with more changeful and hostile ISAR environment without loss of the anti-noise performance and computational efficiency. Simulation results validate the effectiveness of the ISAR imaging approach.

关 键 词：逆合成孔径雷达 立方相位信号 双延时参数化瞬时自相关函数 变尺度操作 高阶模糊函数-吕氏分布 

分 类 号：TN957.52[电子电信—信号与信息处理]