顾及地图投影变形的免像控摄影测量方法  

Photogrammetry without ground control points in the map projection frame

作　　者：段晨汐 李博勋 Duan Chenxi;Li Boxun(College of Geodesy and Geomatics,Shandong University of Science and Technology,Qingdao 266590,China)

机构地区：[1]山东科技大学测绘与空间信息学院,青岛266590

出　　处：《电子测量技术》2023年第8期24-30,共7页Electronic Measurement Technology

基　　金：国家自然科学基金(42171439)项目资助。

摘　　要：无地面控制点的无人机摄影测量可以有效提高生产效率,降低生产成本,在人无法到达的地区展现出很大的优势,但是该方法也存在的一系列问题。一是通过在任检校的方法无法获取准确的相机参数,不准确的相机主距会严重影响目标点的高程。二是在地图投影坐标系下进行测绘任务时,投影变形和地球曲率对高程精度也有影响。因此,本文通过分析高程误差产生的具体原因,实现了在带有架构航线的地心坐标系中相机的自校准,然后,在不带架构航线的地图投影坐标系中获得影像的外方位元素,最后,对地图投影变形和地球曲率引起的高程误差进行了校正。实验结果表明,两组数据的高程均方根误差分别从0.298 m和0.374 m降低到了0.075 m和0.080 m,高程精度均优于0.1 m,因此本文的方法可以在无地面控制点的地图投影坐标系内实现精确的地图绘制。Unmanned aerial vehicle photogrammetry without ground control points can effectively improve production efficiency and reduce production costs.This method shows great advantages in areas inaccessible to people.However,there are a number of problems with this method.One of the main problems is that the accurate camera parameters cannot be obtained through the on-the-job calibration method.Inaccurate camera principal distance can seriously affect the object point elevation.The other one is that the projection deformation and earth curvature also have impacts on the elevation accuracy,when the mapping task is carried out in the map projection frame.Therefore,this article analyzes the specific causes of elevation errors and realizes the camera self-calibration in a geocentric frame with control strips.Then,the exterior orientation elements of the images are calculated in the map projection frame without control strips.Finally,the elevation errors caused by map projection deformation and earth curvature are corrected.The experimental results show that the elevation RMSE of the two data sets decreased from 0.298mand 0.374mto 0.075mand 0.080m,respectively.Elevation accuracy are less than 0.1 m.Therefore,the method in this paper can achieve accurate mapping in a map projection coordinate system without ground control points.

关 键 词：高程改正 地图投影坐标系 无人机摄影测量 免像控 构架航线 

分 类 号：P232[天文地球—摄影测量与遥感]