多运动目标ISAR成像方法研究

当雷达波束中包含多个运动目标且目标在距离维无法分辨时,常规的逆合成孔径雷达(ISAR)成像方法难以有效聚焦,成像质量很差。针对此问题,利用回波中多个目标平动多普勒分量近似线性变化但变化历史不同的特点,提出了一种新的多目标ISAR成像方法。该方法先采用基于调频斜率估计的信号分离(CRESS)方法对多目标回波数据中各个目标的回波分量进行分离,然后对分离后的数据分别做成像处理。仿真实验结果验证了该方法的有效性。

Research on ISAR Imaging of Multiple Moving Targets

For multiple targets which are flying within the same antenna beam and cannot be separated in range, the conventional inverse synthetic aperture radar (ISAR) imaging algorithms, which are mainly confined to single target, cannot be directly used to obtain a focused radar image. In this case, the Doppler histories induced by different radial velocities can be used to resolve multiple targets. Under the assumption that the Doppler frequency shifts changed approximately linearly during the observation time, a new algorithm based on chirp rate estimation (CRESS) technique was proposed for multiple target imaging. After the signal separation process using the CRESS technique, the conventional radar imaging algorithms were applied to ISAR imaging for each individual targets. The computer simulation experiments were presented to illustrate the effectiveness of the proposed method.