# Mining Deformation Life Cycle in the Light of InSAR and Deformation Models
## 4 Results  
### Cumulative Surface Deformations  
The DInSAR processing resulted in 59 ascending and 53 descending maps of surface displacements measured in the LOS for the Bytom-III mining area, which cover the year 2017. Neglecting the time shift between the ascending and descending passes of about two days, we used the consecutive maps retrieved from the two types of passes in the 3D decomposition calculation to calculate the east-west and vertical components of displacements (see Equation (2)) referenced to the dates of ascending  
Figure 9: **(a)** The range of the investigated longwalls No. 5 and 6 from seam 503 of the Bytom-III mining area located in the northern part of USCB (see Figure 8 right); **(b)** depth of the longwalls with respect to the sea level. The numbers represent the starting date (YYMM) for extractions from the corresponding panel; **(c)** terrain elevation above the mined area from Shuttle Radar Topography Mission (SRTM) Digital Elevation Model (DEM).  
sequence. The modelled displacements were also calculated in the horizontal and vertical directions according to the acquisition dates of the Sentinel-1 ascending passes. The total sum of DInSAR horizontal displacement shows westward movement of the eastern side of the subsidence trough with a maximum value of 0.50 m and eastward movement of the western side of up to 0.41 m (Figure 10a). The maximum values extracted from the model are as follows: 0.68 m westward motion of the east side and 0.65 m eastward motion of the west edge (Figure 10b). The summarised subsidence from DInSAR results and the model is shown in Figure 10c,d, respectively, with the maximum values for the inspected area of \(-\)1.65 m for DInSAR and \(-\)2.27 m for the model.  
Figure 10 shows that the magnitude of the horizontal and vertical deformations is larger in the model than obtained from DInSAR. It is also clear that the horizontal deformation field in the DInSAR image (Figure 10a) is more uncertain than the model-based deformation (Figure 10b). Moreover, the border location between the east-west positive and negative values is traced along the east border of longwall No. 6, whereas the same border from the model data (Figure 10b) follows the east border of longwall No. 6 first and longwall No. 5 afterwards, which is comparable with the year shift of extraction from 2016 to 2017.  
Another distinct feature is the shift between the location of the maximum subsidence obtained from DInSAR (Figure 10c) and from the model (Figure 10d). The DInSAR-based subsidence maximum is located 0.2 km towards the north in comparison to the model subsidence. The shape of the subsidence trough is different using these two datasets. Radar observations are centred on the minimum point and elongated in the north-south direction, whereas the model data show the subsidence trough to have two almost independent subsidence minimum lines: One in longwall No. 6 and one in longwall No. 5.  
The DInSAR locations with maximum values of vertical displacement have a mean subsidence of 0.04 m \(\pm\) 0.011 m per six days, which is equivalent to \(-\)0.007 m/day or 2.60 m/year. From the model, we calculated the mean value for the maximum expected subsidence as 0.12 m \(\pm\) 0.020 m per six days, which is equal to 0.02 m/day or 7.30 m/year.