线性调频子脉冲步进频信号已经在雷达ISAR成像中获得了一定的应用。文中提出了线性调频步进频雷达在低信 噪比条件下对高速目标ISAR成像的一种新方法。该方法首先对同频点脉冲应用Keystone变换校正距离走动并进行相参 积累以获得高信噪比,从而在较高信噪比下精确估计目标平动速度并有效实施速度补偿,然后通过步进频处理合成距离 维高分辨,从而提高了ISAR成像质量。通过理论分析与计算机仿真证明了文中方法的有效性。

Chirp-subpulse stepped-frequency signal is proved to be useful for radar ISAR imaging. A new method for chirp-subpulse stepped-frequency radar to get ISAR images of high speed target in low SNR situation is proposed in this paper. Keystone transform is firstly applied on pulses with same carrier frequency to eliminate range migration, and coherent accumulation is performed to gain high SNR,resultingly translational velocity of moving target is precisely estimated and velocity compensation is effectively implemented,then range-dimension synthetical high resolution is obtain through stepped-frequency process,ISAR imaging quality is improved via above processes. This method is demonstrated effective by theoretic analysis and computer simulation.