## 3 Methodology and Details of Data Analysis
### Case Study II: Analyzing Movements of the Geodetic Pillar  
In investigating the movements of the ISTA geodetic pillar, an analysis procedure was followed that was similar to the one used for the tall building. Inclination data from two years' campaigns, along with the GPS baseline solutions of each campaign, were analyzed independently using the LSSA method. In the main conclusions of the inclination data evaluations, it was seen that the pillar moved similarly in the 2000 and 2002 periods, and the results from the GPS data analysis supported this conclusion. For a better understanding of the results, we took a closer look at the data and the conditions during the observations. The temperature (in \({}^{\circ}\)C) and the inclination data (in mrad) of the sensor pair are illustrated in Figure 11, and the main statistics of the inclination data are presented in Table 4.  
According to the corresponding temperature graphs and the observer reports, the weather conditions seemed to be generally stable during both campaigns. In observations in the year 2000, the temperature varied between 5 \({}^{\circ}\)C and 32 \({}^{\circ}\)C, with a 2 \({}^{\circ}\)C difference between the two sensors on any given day and increasing to 7 \({}^{\circ}\)C at nights. After the 14 th observation day, the average daily temperature increased, and this appeared to also affect the inclinations of the pillar (see the trend of inclination data, especially of the 2 nd sensor, after the 14 th day of observations in Figure 11). In 2002, the temperatures varied between 3 \({}^{\circ}\)C and 35 \({}^{\circ}\)C. The daily averages appeared to be consistent throughout the campaign. However, it should be noted that the temperatures measured are the values inside the plastic hood  
Figure 10: Coordinate differences of **(a)** the 1 st and 2 nd campaigns **(b)** the 2 nd and 3 rd campaigns **(c)** the 1 st and 3 rd campaigns (in meters) at the deformation benchmarks. Confidence intervals at 99% confidence level are indicated with a transparent layer on the graphs. In spectral analysis results of the inclinations, the hidden periodicities of the movements of the pillar and the building that hosts the pillar were clarified. The data analysis for the year 2000 yields the fact that both the pillar and the building seemed to have similar characters of movement as they did in 2002. In the overall results, the significant peaks with T = 12 h and T = 24 h were identified in the signals by Sensors I and II along the north-south (X-axis) and east-west (Y-axis) directions. The graphs in Figures 12 and 13 verify these conclusions. Table 5 shows the amplitudes of the periodicities. When the periods of the significant peaks are considered, we can recognize the similarity in the resonant movements of the pillar (observed by Sensor-II) and the building (observed by Sensor-I, Figure 5). However, the amplitudes of the periodic signals show that the displacements of the pillar are greater than those of the building. In the 2002 results, the amplitude of the signal with T = 12 h on the X-axis is 5 microradians for the building and 25 microradians for the pillar). The analysis results of both campaigns were proved against each other. \begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline
**Year** & \multicolumn{4}{c}{**2000**} & \multicolumn{4}{c}{**2002**} \\ \hline
**Sensor No\(\backslash\)Axis** & **I\(\mathbf{Y}\)** & **II\(\mathbf{Y}\)** & **I\(\mathbf{X}\)** & **II\(\mathbf{X}\)** & **I\(\mathbf{Y}\)** & **II\(\mathbf{Y}\)** & **I\(\mathbf{X}\)** & **II\(\mathbf{X}\)** \\ \hline
**maximum** & 0.080 & 0.512 & 0.093 & 0.201 & 0.072 & 0.233 & 0.052 & 0.305 \\
**minimum** & \(-\)0.114 & \(-\)0.013 & \(-\)0.114 & \(-\)0.182 & \(-\)0.100 & \(-\)0.077 & \(-\)0.065 & \(-\)0.026 \\
**magnitude** & 0.194 & 0.525 & 0.207 & 0.383 & 0.172 & 0.310 & 0.117 & 0.331 \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Statistics of 2000 and 2002 campaigns: inclinations in mrad, _ISTA geodetic pillar_. Figure 11: Temperature and inclination data of _the geodetic pillar_.