一种改进的高分卫星影像数字表面模型生成方法

An Improved Appoach for Digital Surface Model Generation from High Resolution Satellite Images

摘要:

针对高分辨率卫星立体影像生成数字表面模型（DSM）过程中由于影像几何和辐射差异造成匹配困难和误匹配等问题，综合运用尺度不变特征转换（SIFT）算子和归一化互相关（NCC）算子，并考虑核线和视差约束，提出了一种基于三角网视差约束的影像分层匹配方法，同时对匹配窗口进行自适应优化改进，实现特征点、格网点和特征线的匹配，从高分辨率卫星影像生成DSM。将提出的方法应用于上海崇明WorldView-1和浙江舟山资源三号卫星影像生成对应区域的DSM，与地面控制点和已有DSM对比分析，高程精度与像素分辨率相当，验证了所提出方法的有效性。

关键词:高分辨率卫星影像，影像金字塔，立体影像匹配，数字表面模型（DSM）

Abstract:

Considering the difficulty and problems in image matching for digital surface model (DSM) generation from high resolution satellite images (HRSIs) due to geometric projection and radial distortion, this paper has proposed an improved hierarchical image matching method based on triangle parallax constraints. In the method, scale invariant feature transform(SIFT) and normalized cross correlation (NCC) algorithms are used as well as epipolar geometric constraint and parallax constraint. Meanwhile, improvement is made for matching window adaptive optimization to generate DSM(digital surface model) from HRSIs based on matched feature points, grid points, and feature lines. Experiments were conducted to generate DSMs using HRSIs including WorldView-1 of Chongming island in Shanghai and ZY-3 of Zhoushan islands in Zhejiang province, and the effectiveness of the proposed approach was validated by control points and an existing DSM, with pixel level height accuracy achieved.

Key words:high resolution satellite imagery, image pyramid, stereo image matching, digital surface model (DSM)