基于双曲线性修正斜距模型的弹载SAR成像方法  

Imaging method for missile-borne SAR based on model of hyperbolic slant range with linear modifying

作　　者：周松[1] 杨磊[1] 周鹏[1] 邢孟道[1] 保铮[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,陕西西安710071

出　　处：《系统工程与电子技术》2013年第6期1168-1176,共9页Systems Engineering and Electronics

基　　金：国家自然科学基金(61001211;61201284);中央高校基本科研业务费专项资金(K5051302013);航空基金(20110181004)资助课题

摘　　要：在弹载合成孔径雷达(synthetic aperture radar,SAR)下降段成像中,由于弹体存在较大的俯冲下降速度和加速度,回波信号的二维频谱表示式难以有效获得,给后续成像处理带来困难。针对该问题,提出了一种基于双曲线性修正斜距模型的弹载SAR成像方法,通过构造双曲函数形式的斜距表示式并引入线性修正因子,对弹载SAR斜距历程进行合理近似;并以修正后的斜距式为基础,利用驻相点原理(principle of stationary phase,POSP)直接求解SAR回波信号的二维频谱;随后根据该频谱表示式设计有效的弹载SAR频域成像算法。该方法下的频谱推导较为简洁,所获得频谱的数学表达式清晰直观,利于成像分析和后续处理。最后的点目标成像仿真验证了该方法的有效性。Owing to the high diving velocity and acceleration in the downward movement for missile borne synthetic aperture radar （SAR）, the accurate expression of SAR echoes in the 2-dimensional （2-D） spectrum is difficult to be derived, which makes the follow up imaging processing difficult. To solve this problem, an ima- ging method for missile borne SAR based on the model of the hyperbolic slant range equation with linear modif- ying is proposed. By simplifying the range history with a hyperbolic slant range expression and incorporating a linear modifying component, the 2-D spectrum for SAR echoes can be derived via the principle of stationary phase （POSP）, by means of which the high-efficient frequency domain SAR algorithm can be well designed. In the proposed method, the derivation of the 2-D spectrum can be simplified and the obtained expression is concise with clearer meanings, which is convenient for signal analysis and imaging processing. Results from point tar- gets simulation are provided to validate the effectiveness of the proposed method.

关 键 词：弹载合成孔径雷达 双曲斜距 线性修正因子 驻相点原理 

分 类 号：TN957[电子电信—信号与信息处理]