面向目标结构信息保持的SAR真正射遥感影像生成方法

True Digital Ortho Maps Production for Target Structure Information of SAR Remote Sensing Images

SAR遥感影像中的几何结构信息对于目标识别和判读具有十分重要的意义。现有SAR遥感影像的正射校正方法沿用光学正射影像(DOM)的校正思路,直接利用物方-像方采样进行,SAR遥感影像叠掩现象所引起的几何畸变会对目标结构信息提取造成干扰。针对以上问题,该文提出一种面向目标结构信息保持的SAR真正射影像(TDOM)制作方法,基于高精度数字表面模型(DSM),通过像方-物方反投影提取像方影像中的叠掩区域;然后,针对叠掩区域进行多高程面投影拟合分析,将雷达波与物方高程最高处的交点作为真实物方投影点,生成单视向SAR真正射影像;最后,利用不同视向的SAR真正射影像进行缺失信息补偿,得到融合后的多视向SAR真正射影像。以高分三号SAR影像作为研究对象,实验结果表明,相比于传统SAR正射影像,该文所提方法能够更好地保持目标结构信息,有效提升处理后SAR影像的目标识别和判读能力。

The restoration of geometric structural information in Synthetic Aperture Radar(SAR)remote sensing images is of great significance for target recognition and interpretation.Existed Digital Ortho Map(DOM)production methods for SAR images follow the traditional ortho-rectification methods of optical images.The application of directly object image sampling can not eliminate the geometric distortion caused by the layovers of SAR remote sensing images.Therefore,a method for the production of SAR True Digital Ortho Map(TDOM)is proposed in this paper.With the help of high-precision Digital Surface Model(DSM)data,the layover area is extracted through the back-projection from image-space to object-space.The highest intersection of the DSM and the back-projected lines are considered as the object mapping of the coordinates in layover area to generate the single-view SAR TDOM.Finally,single-view SAR TDOMs are fused together for information compensation,and the multi-view SAR TDOM is produced with multiple information.Images obtained from the GF-3 SAR satellite are experimented,and the results indicate that the structural information of the target in the TDOMs produced by the proposed method is more clearly than traditional produced DOMs.The application of the proposed method can effectively improve the efficiency of target recognition and interpretation in SAR images.