## 3 Results and Discussion
### Angle Variation  
In Table 3, the series are presented (named C1-C36 and associated with Figures 5-7) associated with different combinations of height and overlap. Each series includes the five angle combinations. Figures 5-7 show, respectively, the results of the experiment carried out. The horizontal axis corresponds to the variation or combination of camera angle for photo acquisition, while the vertical axis is the average error for potholes for depth (Figure 5), width (Figure 6), and volume (Figure 7). The sub-figures correspond to the different severity levels of each of these parameters: (a) low, (b) medium, and (c) high. On the other hand, the curves correspond to the different combinations in Table 3, starting with C1 (lighter color, lower height of photograph) to C36 (stronger color, the higher height of photograph). Thus, for each set of graphs, when the curves are located in the lower areas of each graph, it will represent that this combination Cn has a lower percentage of error in the measurement with the method used, with respect to its real value. On the other hand, those located in the upper \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Resolution [MP]** & **Focal Distance [mm]** & **Shutter Speed [s]** & **Sensor Size [mm]** \\ \hline
20 (\(5472\times 3648\)) & 8.8 & \(\frac{1}{200}\) a \(\frac{1}{8000}\) & \(12.83\times 7.22\) \\ \hline \hline \end{tabular}
\end{table} 
Table 2: UAV Phantom 4 Pro flight features. \begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Combination [\#]** & **Height [m]** & **Overlap [\%]** & **Combination [\#]** & **Height [m]** & **Overlap [\%]** \\ \hline C1 & 2 & 75 & C19 & 15 & 85 \\ C2 & 2 & 80 & C20 & 15 & 90 \\ C3 & 2 & 85 & C21 & 20 & 75 \\ C4 & 2 & 90 & C22 & 20 & 80 \\ C5 & 5 & 75 & C23 & 20 & 85 \\ C  
part will have errors close to or equal to 100%; that is, in the latter case, it has not been possible to completely digitally reconstruct the pothole and the parameter of interest has not been measured. Figure 5 displays the depth error values for each of the series, each including the variation and combination of camera angles for data acquisition. In Figure 5a, it is observed that the incorporation of an oblique angle in the acquisition of photographs produces lower error levels compared to models produced only with vertical photographs; more precisely, the reduction of error is 20%. Then, in Figure 5b,c the same behavior governs, i.e., the inclusion of an oblique angle decreases the error, however, for these severity levels (medium and high), the reduction of the error is much greater, on the order of 30%. Figure 6 displays the width error values obtained from measuring the models of each series with different combinations and angle variations. In Figure 6, it is observed that for this case the inclusion of angle has a minimum impact (less than 2%) for cases with the least error, which are the relevant ones, since those manage to reliably measure the geometric characteristics of potholes. For higher height cases the reduction of the error when incorporating oblique angles is up to 60%, with errors around 50-60%. Figure 7 displays the volume error values, obtained from the measurement of the models of each series with combinations and angle variations. According to the figure, the horizontal axis is the variation or combination of camera angle for photo acquisition, while the vertical axis in Figure 7a-c is the average error of measuring pothole volume by severity level, low in Figure 7a, middle in Figure 7b and high in Figure 7c. In Figure 7, for the best case, the reduction from considering only the vertical angle (90 deg) is 39%. Figure 5: _Cont._  
Figure 5: Average relative depth error behavior for different severity levels. (**a**) Low severity; (**b**) mean severity; (**c**) high severity. Figure 6: _Cont._  
Figure 6: Average relative error severity of width for different severity levels. (**a**) Low severity; (**b**) mean severity; (**c**) high severity. Figure 7: Cont.