改进的机载SAR相位梯度自聚焦算法

相位梯度自聚焦算法的关键步骤是加窗处理,窗宽度的确定决定了成像效果,宽度过大将会引入大量的噪声,反之将无法包含足够成像用的散焦信息.文中针对复杂场景中强散射点的划分不同,提出了一种改进的相位梯度自聚焦方法,该方法通过对强散射点的划分设定阈值,采用门限式加窗方法.与原有相位梯度自聚焦方法成像的比较中,在分辨率和清晰度上优越于原有方法,最后使用机载雷达真实数据对该方法的有效性进行检验.

Improved algorithm of phase gradient autofocus for air-borne synthetic aperture radar

A key step in the algorithm of phase gradient autofocus（PGA） is width of the window, because the determination of the width of the window is very important, if the width of the window is too wide will be mixed with noise, or defocusing cannot contain enough information. In this paper, an improved algorithm of phase gradient autofocus is proposed based on strong distinction between the different scattering, Strong scattering by the algorithm of setting the threshold point of division, using the threshold-type windowing methods. The accuracy of the improved algorithm of phase gradient autofocus is better than the original algorithm, especially in the imaging of point target. Based on real airborne SAR data, the feasibility and validity of the algorithm are demonstrated in conclusion.