基于地理特征的CBERS-02 CCD非正射影像镶嵌研究

非正射影像镶嵌效果与控制点的布局及镶嵌线的选取密切相关。基于地理特征分析,提出一种针对非正射影像的镶嵌方案:将几何精纠正的控制点与影像镶嵌线布设在主体高程面内。遵循此原则,能降低利用推扫式中心投影成像原理获取地形起伏区遥感影像投影差对影像镶嵌的影响。对太原市2006年3月一组CBERS-02 CCD影像镶嵌的实验表明,该方法能够有效削弱甚至消除非正射影像镶嵌中的几何拼接缝。

On Geographic Feature Based Non-Ortho Mosaic of CBERS-02 CCD Images

Non-Ortho RS images are useful in many applications,but there is little research on its mosaic which is crucial in RS images preprocessing.It is considered that images mosaic is a system where the mosaic effect is closely related to the distribution of control points and seam-line.In this paper,after the analysis of geographic feature,the solution scheme of non-Ortho images mosaic is proposed.It can effectively reduce the impact to the images mosaic caused by the projection geometric error in most rolling terrain.The concrete method is as follows:1) The regional mode height surface should be found.2) Precise geometrical correction should be done for each image by collecting those control points distributed on the mode height surface.3) In the overlap areas,an overall optimal seam-line should be sketched out which is attaching to the mode height surface as much as possible.At last,after the colorful matching and overlap areas cutting out,the mosaic image comes into being.In this research,three sheets of CCD images from China-Brazil Earth Resources Satellite(CBERS) on Taiyuan are taken for the experimental data.According to the afore-mentioned method,by picking up some control points in wide riverbeds,all the three sheets are rectified to an existing ETM mosaic image,and the central lines of wide riverbeds in the overlapping areas are extracted as the seam-line.The experimental result indicates that this method can extract an overall optimal seam-line and eliminate the visual texture seam-line effectively even for non-Ortho RS images.