THREE (3) DIMENSIONAL MODELLING WITH CLOSE- RANGE PHOTOGRAMMETRY AND TERRESTRIAL METHOD: A CASE STUDY OF HIGH-RISE STRUCTURES IN FEDERAL SCHOOL OF SURVEYING.

ABSTRACT The correct three-dimensional (3D) modeling of high-rise structures is crucial for various engineering and surveying applications. This study examines the combining of close-range photogrammetry using an unmanned aerial vehicle (UAV) and terrestrial surveying with a total station to produce a precise 3D model of high-rise buildings. The objectives include generating the 3D model, assessing its accuracy, and analyzing the advantages and limitations of both data acquisition methods. The methodology involved UAV flight planning and image acquisition using a DJI Matrice 350 RTK Enterprise drone, with data processed in AgisoftMetashape 2.0 for georeferencing and 3D reconstruction. Terrestrial observations were conducted using a total station to provide exact control points. A total of 21 ground control points (GCPs) were strategically placed on the building for validation. Georeferencing was performed using GCPs, and accuracy was assessed through Root Mean Square Error (RMS) analysis to evaluatedifferences between measured and modeled coordinates. The results demonstrate that UAV photogrammetry enables rapid data acquisition and provides high-resolution imagery, while terrestrial surveying offers more precise coordinate determination. The RMS error analysis highlights accuracy variations between the methods, emphasizing how their integration enhances the precision of 3D modeling. In conclusion, combining UAV photogrammetry with terrestrial surveying improves both accuracy and efficiency of high-rise structure modelling.