针对低信噪比下机动目标的调频步进雷达成像问题,提出基于Radon-分数阶模糊函数(RFRAF)的方法进行积累成像的方法。在分析了机动目标的调频步进雷达回波信号特征的基础上,将目标回波信号在RFRAF域进行匹配和积累,通过峰值搜索出目标的运动参数,并构建补偿函数实现机动目标运动补偿,从而获得目标精确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。

In order to get linearly modulated frequency stepped radar image of maneuvering target in low SNR, a new accumulation imaging method based on Radon-fractional ambiguity function (RFRAF) was proposed. Based on the characteristics of the maneuvering target's linearly modulated frequency stepped radar echo signals, the target's echo signals were matched and accumulated in the RFRAF domain in the pulse repetition period, and the target's moving parameters were estimated by peak searching of the RFRAF spectrums. Then compensation function was constructed to compensate the maneuvering target motion, so as to obtain the accurate ISAR image. Computer simulation results showed that the proposed method could be robust in low SNR.