ACCURACY ASSESSMENT OF 3D PHOTOGRAMMETRIC MODEL FROM UNMANNED AERIAL VEHICLE SYSTEM

Abstract

Unmanned aerial vehicle (UAV) or well known as a drone is a common technique that has been used in the geospatial field for various applications as well as in three-dimensional modelling application. The UAV is an aerial vehicle that does not carry a human pilot, fly remotely or autonomous and able to carry a sensor to collect data. Nowadays, UAV has been widely used in three-dimensional modelling application around the world. It can model an accurate object in a three-dimensional view; besides that, it also can offer a cheaper solution than other techniques or systems. Therefore, the objectives of this research are to evaluate the accuracy assessment of the 3D building model that is generated from a non-metric camera integrated with a multi-rotor UAV system and also to investigate the effect of camera angle toward the quality of the 3D building model. Block T06 of the Faculty of Built Environment and Surveying was selected as a study area in this study. This building is under the management of Universiti Teknologi Malaysia, located in the district of Skudai, Johor. The quadcopter UAV system has been used to capture the high resolution of the building's aerial image from two different perspectives: nadir and oblique. Each set of aerial images were processed using photogrammetric software for producing a three-dimensional model of Blok T06. Two types of 3D building model have produced in this study which are 3D model-based nadir and oblique aerial photo and 3D model based on nadir aerial photo. Ground control point (GCP) and check point (CPs were established in the study area using the GPS rapid-static technique. Later, the processing of aerial triangulation and accuracy assessment were implementing using these points. A statistical equation was used for evaluating the quality of the three-dimensional model was generated in this research. 3D building model based on nadir and oblique aerial photo is more accurate with RMSE ±1.008m compared 3D building model-based nadir aerial photo with RMSE ±1.145m. In conclusion, the 3D building model of block T06 was successfully produced from UAV data based on UAV photogrammetry and the angle of camera also contributes towards the quality of 3D model in aerial photogrammetry.