Application of sar data time series for monitoring of geodinamic prosses in the sofia region

In this study the effect of hazardous geodynamic processes in the area around the city of Sofia is investigated using radar satellite data. The area is of particular interest due to its high population density and high concentration of industrial facilities and residential areas. This highlights the importance of the study area in societal aspect. This the reason the authors set the main objective of this research to be the monitoring of the ongoing geodynamic processes by complementary use of synthetic aperture radar (SAR) and GNNS data. In this paper shown is how the surface deformations in the area of Sofia are analysed using a time series of satellite SAR data from ESA missions. Main advantages of those data are the operational acquisition at fixed intervals and the free access from the ESA repositories which allows creation of interferometric time series produced from SAR data. To densify the time series data from ascending and descending satellite orbits were processed. As final result vector layers containing only those points from the unwrapped interferometric images that exhibit coherence values above the threshold are produced. GNSS data from permanent and regularly measured local geodetic networks are used for validation of the information obtained from SAR data concerning the study area. The results from our research were verified with those from an independent source, in case European Ground Motion Service. Finally to explain the studied geodynamic process in the area data regarding regional geology were used too.