Zhang Yijie, An Pei, Li Zhilong, Liu Qiong, Yang You
Opt Express. 2024 Mar 25;32(7):11346-11362. doi: 10.1364/OE.520677.
An open challenge remained in designing an optical system to capture the aerial image with a wide field of view (FoV) and high resolution. The optical system of one camera from a single unmanned aerial vehicle (UAV) can hardly promise the FoV and resolution. The conventional swarm UAVs can form the camera array with a short or fixed baseline. They can capture the images with a wide FoV and high resolution, but the cost is the requirement of many UAVs. We aim to design a camera array with a wide and dynamic baseline to reduce the demand for UAVs to organize a synthetic optical aperture. In this thought, we propose a master-slave UAVs-based synthetic optical aperture imaging system with a wide and dynamic baseline. The system consists of one master UAV and multiple slave UAVs. Master and slave UAVs provide the global and local FoVs, respectively, and improve the efficiency of image acquisition. In such a system, fusing UAV images becomes a new challenge due to two factors: (i) the small FoV overlap of slave UAVs and (ii) the gap in resolution scale from slave to master UAV images. To deal with it, a coarse-to-fine stitching method is proposed to stitch up the multi-view images into one to obtain a wide FoV with high resolution. A video stabilization method has also been designed for the proposed imaging system. Challenges caused by wide and dynamic baselines can thus be solved by the above methods. Actual data experiments demonstrate that the proposed imaging system achieves high-quality imaging results.
设计一个光学系统以捕获具有宽视场（FoV）和高分辨率的航拍图像仍然是一个公开的挑战。来自单个无人机（UAV）的一台相机的光学系统很难保证视场和分辨率。传统的集群无人机可以形成具有短基线或固定基线的相机阵列。它们可以捕获具有宽视场和高分辨率的图像，但代价是需要许多无人机。我们的目标是设计一个具有宽动态基线的相机阵列，以减少对无人机组织合成孔径的需求。基于这种想法，我们提出了一种基于主从无人机的具有宽动态基线的合成孔径成像系统。该系统由一架主无人机和多架从无人机组成。主无人机和从无人机分别提供全局和局部视场，并提高图像采集效率。在这样的系统中，由于两个因素，融合无人机图像成为一个新的挑战：（i）从无人机的视场重叠小，（ii）从无人机图像到主无人机图像的分辨率尺度存在差距。为了解决这个问题，提出了一种从粗到细的拼接方法，将多视图图像拼接成一幅图像，以获得具有高分辨率的宽视场。还为所提出的成像系统设计了一种视频稳定方法。通过上述方法可以解决由宽动态基线引起的挑战。实际数据实验表明，所提出的成像系统取得了高质量的成像结果。
