DOI: 10.5593/SGEM2016/B22/S10.121


V.E. Oniga, C. Chirila, M. Macovei
Thursday 8 September 2016 by Libadmin2016


Nowadays, Unmanned Aerial Systems (UAS) are a wide used technique in cadastral
applications, providing the acquisition of a high number of images at very high resolution, in a very short time, representing at the same time one of the most attractive and provocative researching domain. Since these platforms are too expensive to be afforded by the average persons, the question of using low-cost UAS arise. Therefore, the accuracy of using this technology in cadastral mapping must be evaluated. To achieve results a small property with the limit defined by 4 points was chosen. First, were determined with high precision by GNSS technology, the coordinates of 10 points, six of them being used as ground control points (GCP), while the remaining 4 as check points (CP) for accuracy assessment. Then, the property 3D model was created as a point cloud which was automatically generated based on digital images acquired with a low-cost UAS, namely DJI Phantom 3 Standard, using the Structure from Motion (SfM) algorithm. Based on this point cloud, also a mesh surface was automatically created. In order to bring the image network results into the national reference coordinate system, different situations were investigated: using the minimum number of GCPs, i.e 3 points, using 4 GCPs, 5 GCPs, respectively all available GCPs, namely 6 points. The property and the existing constructions limits
obtained by UAS technology were compared with the ones measured by tacheometry/GNSS technology while investigating different situations. Finally, the
orthophoto of the study property was generated and analyzed. The preliminary results
showed high potential of using low-cost UAVs in cadastral applications.

Keywords: cadastre, mapping, 3D model, low-cost UAS, accuracy