Defining The Relationship Between The Diameters of The Points Used in 2D Test Platforms and The Parameters Obtained from Camera Calibration

Abstract

With the developing technology in recent years, there has been a significant increase in 3D spatial data needs and data production. 3D spatial data occupy an essential place in almost every field. As a result, there is a need for 3D spatial data production and the produced data's reliability. Like all spatial measuring equipment, cameras, which are data production units used in photogrammetry, must also be calibrated to produce reliable data. Calibration for non-metric cameras is critical to ensure that the measurements made are of high accuracy and at standards acceptable to everyone. In this study, to determine the factors affecting the calibration, terrestrial photogrammetric images were taken with a Canon EOS 600D non-metric camera with different point diameters on the calibration paper. These images were evaluated in the camera calibration software, and the photogrammetric result accuracies were investigated. The effects of the point diameters on the camera calibration paper on the calibration results have been observed. For both calibration papers, A4, A3, A0 sizes were printed and calibrated. As a result of the printouts, as can be predicted, the largest point sizes are A0, which has the largest paper size, and according to the results, it was seen that the highest accuracy was achieved in the A0 dimension. The relationship between the accuracy obtained in the calibration process and the point diameters in the test area was examined in this study. When the 144-point test area presented by the software is printed in A0 size, the point diameters were measured as 1.00 cm. In this study, calibration processes were performed as 1.00 cm, 1.20 cm, 1.40 cm, 1.60 cm, 1.80 cm and 2.00 cm by enlarging the point diameters by 20%, and more accurate results were obtained more easily than other paper sizes and calibration methods. As a result, since the calibration of the device to be used in the studies directly affects the accuracy of the model to be obtained at the end of the study, it is necessary to take the maximum accuracy obtained in the calibration process. In this research, the calibration process's highest accuracy is aimed and how the calibration process can be performed more effortless and more accurately by increasing the size of the point diameter on the test area.