THREE-DIMENSIONAL MODELLING WITH CLOSE RANGE PHOTOGRAMMETRY AND TERRESTRIAL METHOD FOR HIGH-RISE STRUCTURES IN THE FEDERAL SCHOOL OF SURVEYING, OYO

ABSTRACT The need for accurate three-dimensional (3D) modelling of high-rise structures is essential for engineering, surveying, and urban planning. This study focuses on generating an accurate 3D model of the new lecture theatre building using close-range photogrammetry with an unmanned aerial vehicle (UAV) and supporting terrestrial surveying with a total station for georeferencing and accuracy assessment. The objectives include generating a 3D model, evaluating its accuracy, and analysing the strengths and limitations of both data acquisition methods. The methodology involved UAV flight planning and automated image acquisition using a DJI Matrice 350 RTK Enterprise drone, with data processed in Agisoft Metashape for georeferencing and 3D reconstruction. Terrestrial observations were conducted using a total station to determine the coordinates of 20 points on the building, which were used for georeferencing and accuracy validation. The data processing stage included georeferencing using ground control points (GCPs), followed by an accuracy assessment using Root Mean Square Error (RMS) to evaluate discrepancies between measured and modelled coordinates. The results indicate that UAV photogrammetry provides rapid data acquisition and high-resolution imagery, while the terrestrial method offers precise coordinate determination. The RMS error analysis highlights variations in accuracy between close-range photogrammetry and terrestrial surveying method, demonstrating how their integration enhances the precision of 3D modelling. In conclusion, combining UAV photogrammetry and terrestrial surveying improves the accuracy and efficiency of high-rise structure modelling. It is recommended that future studies explore LiDAR technology for further refinement in 3D model generation and accuracy assessment.