## 2 Methodology
### Evaluation of the Quality in the Construction between Point Clouds
#### 2.3.2 Wall Analysis I Cloud-to-Cloud Algorithm  
To determine the degree of inclination of the reinforcements before concreting, a segmentation of the TLS\({}_{\text{SG}}\) part has been carried out. Some results from TLS\({}_{\text{IA}}\) and TLS\({}_{\text{IE}}\) were included that will indicate the inclination and separation between the reinforcements and the face of the formwork. These are taken as a reference to carry out this analysis, since both phases (one and two) were aligned in it. Therefore, the TLS\({}_{\text{IG}}\) point cloud is sectioned through another area of interest, in this case the one on the left side wall (Figure 7).  
Table 2 establishes the distances of the set; in this case, the results are certainly nonsense and different from those of the pillar. This occurs because we compare the internal and external faces of the reinforcement with the internal faces of the wall. Therefore, the value of the average distance of 0.092 m is not representative.  
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Comparison** & **Standard** & **Min.** & **Max. Distance** & **Average** & **Estimated** \\
**between Pilar** & **Deviation (\(\sigma\)) (m)** & **Distance** & **(m)** & **Distance** & **Standard** \\  & & **(m)** & **(m)** & **Error (m)** \\ \hline STEP 1 & 0.0172 & 0 & 0.1151 & 0.0323 & 0.0082 \\ \hline \hline \end{tabular}
\end{table}
Table 1: Result of the comparison between the pillar and the face of the formwork.  
Figure 6: Histogram of Figure 5. Histogram units: meters (X axis) and number of points (Y axis).  
In the same way, it occurs with the maximum distance at which a value of 0.2748 m is observed, which represents the distance between some point on the internal face of the wall and another on the external face of the reinforcement. These data correspond to a normal distribution of the reinforcement spacing, so it is quite close to the 30 cm measured by the wall.  
When interpreting the analysis of the histogram in Figure 8, it must be appreciated that there are a large number of points with values practically equal to 0, most of them representing the soil, which in this case consisted of a larger surface than in the previous analysis.  
Tables 1 and 2 and Figures 6 and 8 show the accuracy of TLS scanners and the cleaning process.  
Of all the total points, 23% correspond both to the ground and to an area of interior reinforcement in which there is a significant deviation from the reinforcement plane, and the values are also very close to 0, as shown in Figure 9.  
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Comparison** & \begin{tabular}{c} **Standard** \\ **Deviation (\(\sigma\))** \\ **(m)** \\ \end{tabular} & \begin{tabular}{c} **Min. Distance** \\ **(m)** \\ \end{tabular} & \begin{tabular}{c} **Max. Distance** \\ **(m)** \\ \end{tabular} & \
\begin{tabular}{c} **Average** \\ **Distance (m)** \\ \end{tabular} &
\begin{tabular}{c} **Estimated** \\ **Standard** \\ **Error (m)** \\ \end{tabular} \\ \hline STEP 1 & 0.0852 & 0 & 0.2749 & 0.0917 & 0.0098 \\ \hline \hline \end{tabular}
\end{table}
Table 2: Result of the comparison between the wall and the face of the formwork.  
Figure 7: Analysis of the comparison between the TLS\({}_{\text{IA}}\) + TLS\({}_{\text{IE}}\) point cloud in the fragment area of the left side wall. Result of applying the Cloud-to-Cloud (C2C) algorithm. Color map of the distribution of distances. On the color scale, red represents the maximum distance expressed in meters.  
The rest of the data obtained are equivalent to the two parts of the reinforcement, the inner face and the outer face. The distances are variable, as can be seen in the inner reinforcement, which has values close to 0.05 m, while the outer face represents values between 0.2 and 0.25 m.  
Figure 9 shows the deviation in the plan of the different reinforcements of the wall. In green is the first line of reinforcements, and in orange is the second line of reinforcements that is closest to the terrain.