采用高阶累积量的调频步进信号逆合成孔径雷达成像新方法  

A New Method for Inverse Synthetic Aperture Radar Imaging of Linear Modulated Stepped Frequency Signals Using High Order Cumulants

作　　者：张龙[1,2] 苏军海[1] 张磊[1] 邢孟道[1] 

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,西安710071 [2]西安工程大学电子与信息学院,西安710048

出　　处：《西安交通大学学报》2010年第4期87-92,共6页Journal of Xi'an Jiaotong University

基　　金：国家自然科学基金重大资助项目(60890072);教育部高等学校博士学科点专项科研基金资助项目(20090203120013);陕西省自然科学基金资助项目(2009JQ8022;2009ZKC02-13);陕西省教育厅自然科学专项资助项目(09JK468);西安工程大学基础研究资助项目(09XG06)

摘　　要：针对在调频步进信号逆合成孔径雷达(ISAR)成像中回波脉冲综合相参化变弱的问题,提出了一种高阶累积量(HOC)频域带宽合成方法.首先建立回波信号在噪声下的HOC表达式,然后对脉组内子脉冲间的误差相位进行估计,再合成一个大带宽线性调频信号,从而获得高分辨一维距离像,最后在方位多普勒域用距离瞬时多普勒方法获得高分辨ISAR图像.与传统方法相比,HOC方法可较好地用于在低信噪比下调频步进信号频带综合.仿真数据处理结果表明,HOC方法在信噪比低于5dB时,其成像效果明显优于传统方法.A band coherent processing method using high order cumulants （HOC） is proposed to improve the weakness of pulses synthesis in inverse synthetic aperture radar （ISAR） imaging of linear modulated stepping frequency signals. Equations of HOC for echoes with Gaussian noise are given, and phase errors between sub-pulses are evaluated. Then a wideband chirp signal is formed by combining the coherent processed sub-pulses, and high range resolution profiles are obtained. Finally, a high resolution ISAR image is generated by applying the range instantaneous Doppler method in cross-range. Simulation and comparisons with the conventional methods show that the HOC method does work properly for bandwidth synthesis under low signal-to-noise ratios （SNR） and that the performance of HOC method outperforms the conventional methods considerably when SNR is below 5dB.

关 键 词：调频步进信号 高阶累积量 低信噪比 频带综合 

分 类 号：TN957.51[电子电信—信号与信息处理]