Ground Calibration of Long-Focal Plane Array Optical Cameras Based on Planar Target and Collimated Light Tube

This paper introduces a rapid ground calibration method for long-focal plane array cameras based on planar chessboard target and collimated light tube. By combining the planar chessboard target with the collimated light tube, an infinitely distant planar target is constructed. A multi-scale image feature extraction method is employed to accurately extract the coordinates of image feature points. A mathematical model for ground calibration of long-focal plane array optical cameras is established. The objective function is formulated based on the minimization of the reprojection error of image feature points, and the intrinsic camera parameters are derived through nonlinear optimization. Physical experiments have verified the feasibility and effectiveness of the ground calibration method proposed in this paper. It is suitable for ground calibration of long-focal plane array optical cameras in a laboratory environment, offering advantages such as high precision, fast speed, and low cost. This method holds significant importance for ensuring high-resolution imaging and high-precision positioning in fields like aerospace and remote sensing mapping.