考虑高层建筑的高分辨率卫星影像几何定位

Geopositioning Capability of Highresolution Satellite Stereo Imagery for Highrise Buildings in Urban Area

摘要:

研究城市高层建筑环境下高分辨率卫星立体影像的几何校正方法和精度分析.实验结果表明,为了提高基于有理函数模型的定位精度,需要加入部分地面控制点.但是当控制点位于地面时,传统物方几何校正模型可以对平坦地面点进行有效几何校正,而建筑物楼顶点会出现高程外推计算错误.为此,提出一种改进的物方几何校正模型,可以消除建筑物高程差过大造成的几何定位影响.计算结果显示,在上海城市中心区域的实验中可以达到平面方向0.6 m和高程方向0.8 m的定位精度,证明了该改进模型的有效性.

关键词:卫星立体影像; 高分辨率; 有理函数模型; 几何校正模型; 定位精度

Abstract:

This paper focuses on the geopositioning capability and accuracy evaluation of highresolution satellite stereo imagery for highrise buildings in urban area.The experimental result shows that ground control points (GCPs) are needed in order to improve the geopositioning accuracy derived from the rational function model (RFM).The traditional geometric correction model in object space is effective when GCPs and independent check points (ICPs) are both on flat ground,but the computation error caused by elevation extrapolation appears when ICPs are on high building rooftops.A modified geometric correction model in object space is then proposed to eliminate the error introduced by huge elevation difference on high buildings.The result shows that a geopositioning accuracy of 0.6m in horizontal direction and 0.8m in vertical direction was achieved in Shanghai central district with high buildings involved,proving the effectiveness of this modified model.

Key words:satellite stereo imagery; highresolution; rational function model; geometric correction model; geopositioning accuracy