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Research on a Synchronized Differential Calibration Method

Aiming at the problem of high-precision image measurement in the wide-area flight test measurement field, a synchronous out-of-region calibration method is proposed. The method first calculates the internal parameters of the camera through a combination of direct linear transformation algorithm and checkerboard calibration method, and then evenly arranges the target in the field of view of the camera, simultaneously acquiring the coordinates of the image point and the three-dimensional coordinates of the total station taken by the camera to form an accurate space Calibration point set. Then, the image plane is divided into N areas in the specified direction, and the external camera parameters are calculated for each area in combination with the method of resection. The experimental results show that after the sub-region calibration, the total error of the camera acquisition points is reduced by 4% (N=3) compared to the global calibration method. The algorithm can realize the calculation of camera parameters in the specified area, which basically meets the industrial measurement requirements of medium and high precision. The research in this paper can be applied to the precise measurement of small displacements in flight tests.