A High-Precision Positioning Method Without Ground Control Points for Mosaic Aerial Survey Camera
Keywords: Mosaic aerial camera, GCP-free, Cloud control, Collimation axis calibration, Bundle adjustment
Abstract. Mosaic aerial survey cameras facilitate large-format imaging by integrating multiple lenses and sensors. Nevertheless, the inherent complexity of their structural design gives rise to collimation axis eccentricity errors between the Position and Orientation System (POS) and the camera's optical center. Conventional methods, which rely on Ground Control Points (GCPs), fall short of fulfilling the demands for high-precision and high-efficiency surveying and mapping tasks. This manuscript presents a ground-control-point-free positioning approach grounded in “cloud control” photogrammetry technology. Leveraging publicly available Google images and Shuttle Radar Topography Mission (SRTM) elevation data as reference sources, a simultaneous solution for the exterior orientation elements of images and the collimation axis eccentricity angle of the Inertial Measurement Unit (IMU) is achieved through bundle adjustment. This process enables rigorous geometric calibration of the camera system. Experimental findings demonstrate that, in the absence of ground control points, the proposed method attains a planar positioning accuracy of 0.29 meters in the x-direction and 0.40 meters in the y-direction, along with a vertical positioning accuracy of 0.78 meters. These results satisfy the surveying and mapping accuracy criteria for a 1:500 scale, underscoring its significant potential for practical engineering applications.
