中文摘要：

针对LFM体制下ISAR雷达在低信噪比下对未知运动目标成像的难题，提出利用调频傅里叶变换的方法进行积累成像方法。在分析了脉间目标LFM回波信号特征的基础上，将目标回波信号在快慢时间域进行联合匹配和积累，通过能量积累后的目标位置估计搜索出目标的精确运动参数，并构建补偿函数实现目标运动补偿，从而获得低信噪比下的精确ISAR像。计算机仿真结果进一步表明了该方法能在低信噪比下稳健成像。

英文摘要：

In order to obtain the unknown motion target imaging under low SNR in the LFM system, a new accumulation imaging method based on frequency modulated Fourier transform was proposed. Based on the characteristics of the target＇ s LFM radar interpulse echo sig- nals, the target＇ s echo signals were jointly matched and accumulated in fast-slow time domain. Through the target position after energy ac- cumulation, the target＇ s accurate motion parameters could be searched ont. After that, the compensation function was constructed to com- pensate the target motion, so as to obtain the accurate ISAR image. Computer simulation results showed that the proposed method could be robust under low SNR.