Three-dimensional modelling of building based on the combination between unmanned aerial vehicle and laser scanning data

Abstract

Unmanned Aerial Vehicle (UAV) is frequently used for obtaining two- dimensional (2D) or three-dimensional (3D) data acquisition. Meanwhile, Terrestrial Laser Scanner (TLS) is used for obtaining only 3D data acquisition. However, if both are combined, they are able to produce a more accurate data. The purpose of this study is to investigate the possible combination of point clouds obtained through the acquisition of data from UAV and TLS at two buildings in Universiti Teknologi Malaysia (UTM), Skudai, Johor which are T06 and T05 buildings. The aim is to generate 3D model of those two buildings. The objectives of this study are; (i) to combine the data through the aerial survey and ground survey by merging their point clouds and develop 3D model from the combination, and (ii) to evaluate the results and the accuracy of the combination process. These objectives were achieved by appropriately merging data from UAV DJI Phantom 4 and TLS Topcon GLS2000 throughout the survey of the roof and facades. The aerial data were processed using Pix4D software and ground data were processed using Scanmaster software. The data combination process was done by converting both point clouds into the same coordinate system and then by aligning the same points of both points clouds in Cloud Compare software. The results were presented in the form of orthophoto, point clouds and 3D model of both buildings. For verification purposes, dimensional survey was done and there were several distances taken from the man-made features of the study area to validate the accuracy assessment. The results of residuals between the dimension survey and combination were measured using the Root Mean Square Error (RMSE) method. Both T06 and T05 buildings were presented as a 3D model based on the point cloud accuracy in cm level. To conclude, the combination between these both UAV and TLS can be implemented to produce 3D model of a building.