A numerical simulation procedure for evaluating the accuracy of 3-dimensional photogrammetric models and its application to geometric parameters of discontinuities in rock masses

This study proposes a numerical simulation procedure to evaluate the accuracy of geometric parameters of 3-dimensional models reconstructed by photogrammetry based on the Open Graphics Library. As a technical mean to obtain photogrammetric photos and data, this method has achieved the goal of controlling the parameters in the photogrammetric process at will. The proposed method is validated by several physical model experiments using the unmanned aerial vehicle Phantom 4 Real-time kinematic (RTK). Through a series of numerical experiments, this study quantitatively analyzes the error of geometric parameters of discontinuities in rock masses caused by coordinate accuracy of camera positions and shooting distance, and some quantitative findings were obtained. These results conforming to common sense also validate the proposed simulation procedure. This numerical simulation procedure has a broad application prospect in guiding and optimization of photo acquisition of field outcrop balancing the accuracy and efficiency.