ASSESSING THE EFFECT OF ALOS-2 DATA UTILIZATION ON THE ACCURACY OF ESTIMATION VERTICAL AND HORIZONTAL DEFORMATION COMPONENTS IN THE AREA OF HARD COAL MINING EXPLOITATION IN POLAND BY USING DIFFERENTIAL SYNTHETIC APERTURE RADAR INTERFEROMETRY

Mining-induced deformations are characterized by high deformation rates. These deformations consist of both vertical and horizontal components, which should not be neglected during the monitoring of such areas. Unfortunately, Differential Satellite Synthetic Aperture Radar Interferometry (DInSAR) can only measure deformations in the line of sight (LOS) direction towards the satellite. Combining data from ascending and descending geometry allows reconstruction of the vertical and east-west deformation components. Theoretically, at least information from one ascending and one descending geometry is enough to reconstruct the vertical and east-west deformation components; however, for the area of interest three various Sentinel-1 datasets (one ascending and two descending) are available and have been used in the study. Furthermore, considering the availability of other SAR missions with slightly different geometries, the objective of this study was to evaluate the effect of ALOS-2 use on the accuracy of estimating the east-west and vertical cumulative deformation component estimated for a time span of approximately one year. Unfortunately, we have access to only five ALOS-2 scenes within the area of interest. However, the comparison of the decomposed results with GNSS measurements shows that the application of additional ALOS-2 data, even five scenes, allows the root mean square error (RMSE) to be decreased for the vertical and horizontal deformation component from 0.038m to 0.032m and from 0.031m to 0.018m, respectively. This means that the application of ALOS-2 data has a positive value on the accuracy of decomposed vertical and horizontal deformation components.