机载拼接式大面阵相机的分块多项式畸变模型

张祖勋(), 赵新博, 段延松()    

A block-wise polynomial distortion model for airborne composite large-format camera

Zuxun ZHANG(), Xinbo ZHAO, Yansong DUAN()   

摘要：

机载拼接式大面阵相机因其高分辨率、广覆盖性等优点在遥感测绘工作中广受欢迎。然而，由于制造工艺、装配精度等因素的影响，相机成像过程中会产生各种复杂畸变，影响影像质量和几何处理准确性。本文针对拼接式航空面阵相机的特点，提出一种分块多项式畸变模型，该模型核心思想是在Brown畸变模型检校残差矢量场引导下，将成像幅面划分为多个子影像块，在每个子块内采用多项式描述畸变，从而实现对各种复杂畸变的有效修正。此外，为求解分块多项式参数，设计了一种云控制检校方案。本文以北京空间机电研究所研制的AFC-900相机为研究对象，在肇东开展相机的云控制检校，然后分别在肇东、介休和汨罗3个测区开展生产验证，结果表明本文提出的畸变模型可以将AFC-900相机的畸变纠正到0.5像素以内，生产成果精度满足1∶500和1∶2000大比例尺测绘规范要求。

关键词: 拼接式大面阵相机, 畸变模型, 分块多项式, 云控制检校

Abstract:

The airborne composite large-format camera has gained widespread popularity in remote sensing and surveying due to its high resolution and wide coverage. However, various complex distortions arise during the imaging process owing to factors such as manufacturing processes and assembly precision, which impact image quality and the accuracy of geometric processing. This paper proposes a block-wise polynomial distortion model tailored to the characteristics of mosaic aerial frame cameras. The core idea of this model is to divide the imaging plane into multiple sub-image blocks guided by the residual vector field from Brown's distortion model calibration, and describe distortions within each sub-block using polynomials, thereby effectively correcting various complex distortions. Additionally, a cloud-controlled calibration scheme is designed to solve for the block-wise polynomial parameters. Taking the AFC-900 camera developed by the Beijing Institute of Aerospace Mechatronics as the research subject, the paper conducted cloud-controlled calibration of the camera in Zhaodong. Subsequently, production verification was carried out in three survey areas: Zhaodong, Jiexiu, and Miluo. The results demonstrate that the distortion model proposed in this paper can correct distortions in the AFC-900 camera to within 0.5 pixels, and the accuracy of the production outcomes meets the specifications for large-scale mapping at scales of 1∶500 and 1∶2000.

Key words: airborne composite large-format camera, distortion model, block-wise polynomial, cloud-controlled calibration