摆扫成像系统的航带覆盖面积较大，在测绘中应用中具有很高的影像采集效率。但由于摆扫影像同名点的交会角小、交会条件弱，不适合采用传统区域网平差方法进行处理。本文以中国APS7K摆扫相机系统为研究对象，分析了其成像原理后，提出了对APS7K摆扫相机数据进行空中三角测量处理的方法。该方法首先根据POS数据和影像轨迹信息确定邻接矩阵，之后，为克服单航带交会弱问题引入数字高程模型(DEM)并应用到区域网平差中，通过迭代求最优解。为验证本方法的有效性，使用多航带正射影像拼接以及谷歌地球数据对比进行检查。结果表明，该方法可将重投影误差减小到亚像素，完全消除了正射拼接的不一致性，在有控制点情况下，绝对误差优于0.4米(地面元大小0.2米)。文章最后总结了该方法的不足之处，并对未来研究进行了展望。
Digital Elevation Model-Assisted Aerial Triangulation Method On An Unmanned Aerial Vehicle Sweeping Camera System
welcome to cit:
Zhao, X., Zhou, Q., Dong, J. and Duan, Y. (2022), Digital Elevation Model-Assisted Aerial Triangulation Method On An Unmanned Aerial Vehicle Sweeping Camera System. Photogram Rec, 37: 208-227. 
https://doi.org/10.1111/phor.12419
Abstract
The sweeping camera systems in the surveying and mapping industry are usually efficient in image acquisition, for the photography coverage of a single strip is relatively large. The triangulation angle of correspondence is overly tiny to adopt traditional block adjustment (BA). This study analysed the imaging principle of the Chinese APS7K comprehensive camera system and proposed an aerial triangulation method for the data this system acquired. The proposed method first determines the adjacent matrix from the POS data and trajectory information. The other part of the method is to overcome the weak relative geometry in a single strip by introducing the digital elevation model (DEM) data into the block adjustment scheme. The optimal solution of adjustment is obtained by iteratively solving the problem. We verified the optimisation's effectiveness by checking stitched orthophoto and check points from Google Earth. The results show that mosaic discrepancy is eliminated, the reprojection error is reduced to subpixel level, and positioning accuracy is better than 0.4 meter (ground sample distance is 0.2 meter) after adjustment with ground control points. Finally, the method’s shortcomings and prospects are summarized.
