## 5 Data Analyses and Results
### DIC Analyses
#### 5.2.3 Analyses of the Landslide Deformation  
The deformation of the Montescalioso landslide area (Figure 6) was measured for each dataset shown in Table 1 using both the COSI-Corr and GOM Correlate software, setting a correlation threshold of 0.9. The best parameters for use in each analysis were identified through a trial and error approach, and the results are shown in Table 4.  
Displacement maps of each analysis are reported in the following figures, except for the descending CSK SAR absolute amplitude dataset, which is characterized by a moderate percentage of areas affected by the decorrelated signal and is hence unrepresentative (Figures 10-15). The displacement pattern of the Montescalioso landslide was inferred from an analysis of Figures 10-15. All the processed maps show that the amount of displacement increases from the NW sector (~2-3 m) to the central part of the landslide and the toe, and the value is as large as 20-21 m. Moreover, similarities are observed in the amount of movement as well as in the direction of the landslide displacement field. In fact, the inferred vector fields show a direction that is generally towards the S-SE in the NW sector but S-SW in the NE sector, thus reaching a prevalent SW direction in the central portion. \begin{table}
\begin{tabular}{c c c c} \hline \hline  & \multicolumn{3}{c}{**Master Image: 3 December 2013**} \\ \hline
**Post-Failure** & **Time Span from** & **Time Span from** & **Pixels Affected by** \\
**Images (Slaves)** & **Master Image (gg)** & **Master Image (years)** & **Decorrelated Signal (\%)** \\ \hline
18 December 2013 & 15 & 0.04 & 32.0 \\
23 December 2013 & 23 & 0.06 & 44.8 \\
3 January 2014 & 31 & 0.08 & 30.2 \\
4 February 2014 & 63 & 0.17 & 42.2 \\
20 February 2014 & 79 & 0.22 & 41.1 \\
8 March 2014 & 95 & 0.26 & 41.3 \\
9 April 2014 & 147 & 0.40 & 43.6 \\
25 April 2014 & 163 & 0.45 & 45.5 \\
11 May 2014 & 179 & 0.49 & 45.9 \\
12 June 2014 & 211 & 0.58 & 44.8 \\
28 June 2014 & 227 & 0.62 & 46.6 \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Pixel percentage affected by the decorrelated signal increases as the time span between the processed images increases. Figure 9: Temporal resolution effect on the decorrelation signal. A direct relationship was achieved, which is also perceptible from the trend line (dashed black line). \begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline \multirow{2}{*}{**Dataset**} & \multicolumn{4}{c}{**COSI-Corr**} & \multicolumn{4}{c}{**COM Complete**} \\ \cline{2-9}  & \multicolumn{2}{c}{**Frequency Centralize Engine**} & \multicolumn{2}{c}{**Surface Component**} & \multicolumn{2}{c}{**Bottom System Quality Tool**} & \multirow{2}{*}{**Scale Calibration**} \\ \cline{2-9}  & **Window Size (pixels)** & **Star (pixels)** & **Window Size (pixels)** & **Point Distance (pixels)** & **Window Size (pixels)** & **Point Distance (pixels)** & **Scale Calibration** \\ \hline CXS-SAR absolute ASC & 128 & 4 & 20 & 5 & 20 & 5 & Monthly defined scale \\ \hline CXS-SAR absolute DESC & 256 & 8 & 50 & 5 & 50 & 5 & Monthly defined scale \\ \hline CXS-SAR improved average DSC & 64 & 2 & 20 & 5 & 20 & 5 & Monthly defined scale \\ \hline EMSS-SAR-improved average DESC & 128 & 4 & 50 & 5 & 50 & 5 & Monthly defined scale \\ \hline LANDSATS SOL-THES & 16 & 2 & 50 & 5 & 50 & 5 & Monthly defined scale \\ \hline Should Distorms & 64 & 4 & 50 & 5 & 15 & 5 & Monthly defined scale \\ \hline HR Object Orthophote & 128 & 8 & 50 & 5 & 15 & 5 & Monthly defined scale \\ \hline \hline \end{tabular}
\end{table} 
Table 4: DIC setting parameters used in COSI-Corr and GOM Correlate processing. Figure 11: DIC displacement map retrieved from ascending CSK SAR temporal average amplitude images with COSI-Corr (**A**) and GOM Correlate (**B**) software. The white arrows show the displacement vector field. The red polygons show the landslide boundary. The stable area surrounding the slope failure area is clearly characterized as having no movement. Grey coloring corresponds to areas with loss of correspondence between the pre- and post-failure images.