## 3 Results and Discussion
### Variation in Overlap and Height
At 15 m, the least error was obtained (0.8%) with an overlap of 80%, which has between 0.4 and 0.5% less error compared to overlaps of 90 and 75%, respectively, moreover, the error is reduced by 0.9% compared to the overlap of 85%. At 20 m, the least error is obtained with an overlap of 80%, which is 1.6% and is 0.3% lower compared to the overlap of 90%, moreover, the error is reduced by 1.5% to 2.4% compared to overlaps of 75 and 85%. At 25 m, the least error was obtained (2.8%) with an overlap of 80%, which is between 0.7 and 2.6% less error compared to the other overlaps (75, 85 and 90%). At 30 m, the least error was obtained (5.7%) with an overlap of 90%, which has 1.4% less error compared to an overlap of 80%. Moreover, the error is reduced by 4 to 4.3% compared to overlaps of 75 to 85%. At 40 m, the least error was obtained (11.4%) with an overlap of 90%, which has 1.8% less error compared to overlaps of 80 and 85%. Moreover, the error is reduced by 11.5% compared to an overlap of 75%. Figure 10 shows the values and behavior of the volume measurement error by varying the height and overlap in vertical photo acquisition flights (90-degree camera angle) for different severity in potholes (low severity in Figure 10a, middle severity in Figure 10b, high severity in Figure 10c). Figure 10: Cont. In Figure 10a, a trend is observed of overlapping error increases as the measurement height grows. On the other hand, it is observed that the error at 10 m is greater than 60% for all overlaps, indicating that the experiment does not work well for this type of analysis. At 2 m, the minimum error was 4.1%, which is associated with an overlap of 80%, this error is 2% lower compared to an overlap of 85%, even more the error is reduced by more than 3.6% compared to overlaps of 75 and 90%. At 5 m, the 80% overlap has the lowest error (6.4%), an error that is 9.2% less compared to an overlap of 85%. Moreover, the error is reduced by more than 9.4% compared to 75 and 90% overlaps. At 8 m, the least error (36.6%) was obtained with a 90% overlap. For 10 m and with an overlap of 75% an error of 63.1% was obtained, which is the lowest for this height, since it has 5.5% less error compared to the overlap of 80%. Moreover, the error is reduced by 12.8 to 18.7% compared to the overlaps of 85 and 90%. At 15 m, the least error was obtained (81.9%) with an overlap of 90%, which is between 2.9 and 10.1% less error compared to the other overlaps (75, 80 and 85%). At 20 m, the error is 95% for an 80% overlap, which is high for further analysis of this type of measurement. So, from 20 m, an analysis of volume for low severity potholes loses value in practice, since the volume of the pothole fails to describe a semi-sphere, but rather tries to reconstruct a kind of cone, from the position in which the maximum depth was obtained. The behavior is similar to that observed in the pothole depth analyses, as the measured volume depends directly on how good the measurement has been with respect to depth and area characteristics. From Figure 10b, a trend is observed of overlapping error increases as the capture height grows. On the other hand, it is observed that the error at 10 m is greater than 30% for overlaps of 75 and 80% and more than 50% for overlaps of 85 and 90%, indicating that the experiment does not work properly for this type of analysis. However, the error is reduced from what was observed in the previous analysis. At 2 m, the minimum error was 1.9%, which is associated with an overlap of 85%, this error is 1.8% lower compared to an overlap of 90%, even more so the error is reduced by more than 2.3% compared to overlaps of 75 and 80%. At 5 m, the 80% overlap has the lowest error (7.3%), an error that is 7.5% less compared to a 90% overlap. Moreover, the error is reduced by more than 7.8% compared to 75 and 85% overlaps. At 8 m, the least error (22.5%) was obtained with a 90% overlap.