Three-Dimensional Measurement of Large-Scale Objects Using Photogrammetry Based on Total Station

Based on photogrammetry, this study aims to determine a highly accurate, efficient, and flexible approach for obtaining three-dimensional shape and color information of large-scale objects using a total station and a common digital camera. An ordinary digital camera was rigidly connected to the telescope of a total station to build a combined measurement system, and the camera's posture was recorded at all times using the angle reading of the total station. To weaken the parameter coupling while calibrating a camera with a narrow field of view, the principal distance parameter was first directly calibrated based on the physical characteristics of the camera. The other intrinsic parameters of the camera and pose parameters of the telescope associated with the camera were determined by establishing a control field. The station was freely transformed using two common points to achieve the three-dimensional measurement of large-scale objects. Experiments show that the relative error of the length achieved using this method does not exceed +/- 1/100, and the angle error does not exceed +/- 0.6 degrees, implying that this method can currently realize three-dimensional measurement of large-scale objects with medium accuracy.