摘要
相位梯度自聚焦 ( PGA)算法是一种稳健的高分辨 SAR相位校正方法 ,在 SAR领域得到广泛应用。但PGA是对聚束模式成像提出的 ,不能直接用于条带模式。本文利用两种模式之间的内在联系 ,将条带模式 SAR数据分块处理 ,等效成聚束模式数据。然后 ,用聚束照射 SAR成像算法实现成像 ,此时就可以利用 PGA完成各块子图像的自聚焦过程 ,最后将各子图像适当拼接 ,从而实现条带模式 SAR的 PGA处理 ,外场数据的处理证实了本文方法的可行性 ,同时 ,分块处理条带 SAR数据实现了聚束照射 SAR与条带模式 SAR成像算法上的统一。
The phase gradient autofocus (PGA) algorithm, used in SAR community is proven to be a superior phase error correction method for fine resolution SAR. The PGA technique for spotlight mode imaging, however, cannot be directly applied to image formed in the stripmap mode. Based on the inherent relation between spotlight mode SAR and stripmap mode SAR, a modified approach is presented. Firstly, the stripmap data are provided to several segments equivalent to spotlight data. Next, sub-image formation is performed by spotlight imaging algorithm. At this point, PGA can be used on sub-images to improve image quality. Finally the subimages are logically mosaiced and stripmap mode PGA is accomplished. The processing results of live data show the method. Additionally, subpatch processing to stripmap SAR data realizes the unification of spotlight and stripmap SAR image formation algorithm.
出处
《数据采集与处理》
CSCD
2002年第4期437-440,共4页
Journal of Data Acquisition and Processing
