Using Unmanned Aerial Vehicles (UAV) for High-Resolution Reconstruction of Topography: The Structure from Motion Approach on Coastal Environments

Remote Sensing

Francesco Mancini³  Marco Dubbini¹  Mario Gattelli⁴  Francesco Stecchi²  Stefano Fabbri² 

[1]DiSCi, University of Bologna, Piazza San Giovanni in Monte 2, I-40124 Bologna, Italy

[2] E-Mail:

[3]BiGeA, University of Bologna, via Sant’Alberto 163, I-48123 Ravenna, Italy

[4] E-Mails:

[5]DICATECh, Technical University of Bari, via Edoardo Orabona 4, I-70125 Bari, Italy

[6]SAL Engineering, via Vittorio Veneto 2, I-41124 Modena, Italy

[7] E-Mail:

关键词: UAV;    structure from motion;    terrestrial laser scanning;    digital surface model;    beach dunes system;   

DOI  :  10.3390/rs5126880

来源: mdpi

【 摘 要 】

The availability of high-resolution Digital Surface Models of coastal environments is of increasing interest for scientists involved in the study of the coastal system processes. Among the range of terrestrial and aerial methods available to produce such a dataset, this study tests the utility of the Structure from Motion (SfM) approach to low-altitude aerial imageries collected by Unmanned Aerial Vehicle (UAV). The SfM image-based approach was selected whilst searching for a rapid, inexpensive, and highly automated method, able to produce 3D information from unstructured aerial images. In particular, it was used to generate a dense point cloud and successively a high-resolution Digital Surface Models (DSM) of a beach dune system in Marina di Ravenna (Italy). The quality of the elevation dataset produced by the UAV-SfM was initially evaluated by comparison with point cloud generated by a Terrestrial Laser Scanning (TLS) surveys. Such a comparison served to highlight an average difference in the vertical values of 0.05 m (RMS = 0.19 m). However, although the points cloud comparison is the best approach to investigate the absolute or relative correspondence between UAV and TLS methods, the assessment of geomorphic features is usually based on multi-temporal surfaces analysis, where an interpolation process is required. DSMs were therefore generated from UAV and TLS points clouds and vertical absolute accuracies assessed by comparison with a Global Navigation Satellite System (GNSS) survey. The vertical comparison of UAV and TLS DSMs with respect to GNSS measurements pointed out an average distance at cm-level (RMS = 0.011 m). The successive point by point direct comparison between UAV and TLS elevations show a very small average distance, 0.015 m, with RMS = 0.220 m. Larger values are encountered in areas where sudden changes in topography are present. The UAV-based approach was demonstrated to be a straightforward one and accuracy of the vertical dataset was comparable with results obtained by TLS technology.

【 授权许可】

CC BY   
© 2013 by the authors; licensee MDPI, Basel, Switzerland