条带合成孔径雷达成像的DJ-PGA修正算法

Extended DJ-PGA Algorithm for Stripmap Mode SAR

用于解决条带SAR成像自聚焦问题的DJ_PGA算法,因没有选取有利于相位误差估计的全部强点目标,以及未能对数据进行自适应加窗处理,致使在处理实测数据时会出现相位误差估计不准,造成图像聚焦效果不一致的问题。针对上述问题,该文提出了DJ_PGA修正算法,并对其进行了详细阐述。通过对文中所给出的不同算法Etna火山口实测数据条带SAR成像仿真图分析可以看出,修正PGA算法对实测数据具有更强的适应性。

The algorithm of phase gradient autofocus（PGA） for stripmap SAR proposed by Douglas and Janes has some defects in estimating phase error precisely in the real data. Because Douglas and Janes＇ autofocus method does not completely select power- point object for estimating the phase error, and does not use self- adaptive weighting. In this paper, three methods used to improve the DJ-PGA algorithm are introduced in detail. All these make extending PGA algorithm for more powerful adaptability. The emulational experiment results of Etna crater using different methods are also provided .