基于多基线影像匹配的高分辨率遥感影像DEM自动生成

Multi-image matching for DEM generation from satellite imagery

文章提出了一种新型的基于多基线影像匹配的高性能、高精度DEM自动生成方法,该方法采用由粗到细的多级影像匹配策略,综合多种成熟的,性能互补的影像匹配算法,充分考虑高分辨率卫星影像的特点,可以获取成像区域的高精确DEM。文章以青南高原三江源实验区为例,采用SPOT-5 HRS立体影像和HRS/HRG三立体像对生成实验区1:50 000的25m间隔DEM,并利用大量外业和内业检查点对自动提取的DEM进行精度分析。实验结果表明,利用本文提出的影像匹配方法可以从SPOT-5卫星影像中全自动生成1:50 000DEM,其高程精度优于国家测图规范的要求最低50%以上;另外,SPOT-5HRS/HRG三影像立体条带数据适用于地势起伏较大的深切割山地区域,采用本文提出的基于多基线的高精度匹配算法,可以同时保持自动生成的DEM的精度和可靠性。大大减少自动生成的DEM中存在的粗差和人工后处理的工作量。

In this paper,we present an advanced matching approach for automatic DEM generation from high-resolution satellite images.It can provide dense,precise and reliable results.The method matches multiple images simultaneously and it uses a coarse-to-fine hierarchical solution with an effective combination of several image matching algorithms and automatic quality control.The DEMs are generated by combination of matching results of feature points,grid points and edges.The proposed approach has been applied to SPOT-5 HRS/HRG images over a testfield in Zone of headstream of Three rivers,Tibet Plateau,China with variable terrain geomorphologic type.The accuracy tests were based on the comparison between as many as 300 accurate GPS check points,more than 1400 manually measured check points and the automatically extracted DEMs.The RMS errors for the whole area are 2-6 m,while for flat/ hilly areas the accuracy is about 2-3 m or even better.It's shown that with the proposed automatic DEM generation approach,by using SPOT-5 HRS/HRG imagery,satisfactory 1:50000 DEMs can be completed with a better accuracy than those requirements from Chinese Surveying and Mapping regulations.