在高分辨逆合成孔径雷达成像中,目标的转动会在回波信号中引入时变的多普勒调制,导致距离空变的相位误差,同时传统的平动相位误差补偿也会因没有考虑转动相位误差而性能严重下降.因此,提出了一种联合的相位自聚焦方法,实现对平动和转动的相位误差的联合校正.首先根据最小熵准则将联合相位误差转化为距离非空变和距离空变的相位误差,然后运用基于拟牛顿的坐标梯度下降法实现对最小熵优化问题的求解.
In high-resolution inverse synthetic aperture radar imaging, the rotational motion of the targets tends to introduce the time-variant Doppler modulation in the echo, which acts as the range-variant phase errors in phase history. Moreover, the performance of translational phase error compensation may be dramatically degraded without properly considering the range-variant phase errors. In this paper, an approach to joint translational and rotational phase auto-focusing is proposed. In the procedure, the joint phase error correction is modeled as range-invariant and range-variant phase errors using a metric of minimum entropy. Then the minimum-entropy optimization is solved by employing a coordinate descend method based on the quasi-Newton solver. Finally, experiment based on simulated data is performed to confirm the effectiveness of the proposed algorithm.