## 3 Results
### Field Tests and Applications under Real Conditions  
In this section, we reported the data analysis of field tests and performed under real and dynamic conditions (second, third and fourth case study). Examples of the scans of the statue, the room and the rests of the Doric column are presented in Appendix B (Figure A4). In the analysis phase of the second case study, we focused on the shaft of the statue; therefore, the point cloud was appropriately sectioned in the middle of the shaft for analysis. From the analysis of the point cloud, it was easy to detect and isolate a drift problem for the iOS device during the scanning phase at a distance of 3 m. In Figure 11, the extent of the drift can be estimated using the metric bar. The problem did not occur for the iOS and Android scans at 2 m; the sections of these latter scans are shown in Appendix B (Figure A5a,b). In Table 4, we reported the values of surface variation and ommivariance obtained from the scans; the highest value of SV\({}_{\lambda}\) was associated with the scan where the drift problem occurred. Additionally, observing the ommivariance value, it can be seen that the inhomogeneity of the point cloud increases as the SV\({}_{\lambda}\) value increases. Figure 10: Comparison of mean planarity values for samples scanned at a distance of 0.5 m. \begin{table}
\begin{tabular}{c c c} \hline \hline
**Resolution** & **R\({}^{2}\) for Scanning Distance:** & **R\({}^{2}\) for Scanning Distance:** \\  & **0.5 m** & **1.5 m** \\ \hline
1 cm (iOS) & 0.54 & 0.68 \\
1.5 cm (iOS) & 0.53 & 0.40 \\
2 cm (Android) & 0.27 & 0.20 \\ \hline \hline \end{tabular}
\end{table} 
Table 3: R\({}^{2}\) values obtained by linear regression between sample albedo and surface variation values. The scan performed with the Android device at 3 m produced no results (it did not acquire any points); this indicates that the range of the device is less than 3 m. Figure 11b,c presents additional images of the point cloud affected by drift problems. Figure 11d shows a section (C-C) executed in the area of the scan closure, and Figure 11c shows a top view of the statue. Table 5 shows the surface variation and planarity values for the third case study. Figure 12 shows the room planimetry obtained by dissecting the point clouds at a height of approximately 1.50 m (the scalar field represents the planarity values). Looking at the planarity values in the table, it can be seen (see Figure 12) that the Android device performed unsatisfactorily for geomatics purposes. The iOS values, on the other hand, were quite encouraging for the scans performed at both 1 and 1.5 cm. The fourth case study involved the scanning of the remains of a Doric column located in Taranto. We performed three scans with resolutions of 1 cm (iOS), 1.5 cm (iOS) and 2 cm (Android). In Table 6, we reported the surface variation and omnivariance values obtained for the three scans. Observing the values, it can be seen that the scan made at a resolution of 1.5 cm (iOS) was the worst. In order to identify possible drift and splitting of the surface, we carried out sections of the point cloud in the vertical (sect. A-A) and horizontal (on the third column drum sect. B-B) scan closing zones (Figure 13). Figure 14 presents the A-A and B-B sections carried out on the three point clouds. In particular, Figure 14a,d shows the sections taken on the 1 cm resolution scan, Figure 14b,e shows the sections carried out on the 1.5 cm resolution scan and Figure 14c,f shows the sections carried out on the 2 cm resolution scan. \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Object Scanned** & \multicolumn{3}{c}{**Scan Distance: Adapative**} \\ \hline \multirow{3}{*}{Doric column rests} & SV\({}_{\lambda}\) 1 cm & SV\({}_{\lambda}\) 1.5 cm & SV\({}_{\lambda}\) 2 cm \\ \cline{2-4}  & 0.0400 & 0.0682 & 0.0309 \\ \cline{2-4}  & O\({}_{\lambda}\) 1 cm & O\({}_{\lambda}\) 1.5 cm & O\({}_{\lambda}\) 2 cm \\ \cline{2-4}  & 0.0019 & 0.0022 & 0.0018 \\ \hline \hline \end{tabular}
\end{table}