Zusammenfassung
Summary
In this study, three highlights of Sentinel-1 (S-1) Interferometric Synthetic Aperture Radar (InSAR) over Germany are presented to evaluate the potential and opportunities provided by this European SAR mission. Firstly, large-scale interferometry across the country is presented and analyzed against atmospheric models from ERA-Interim and GNSS (Global Navigation Satellite System) to assess the perspective provided by S-1 for atmospheric modeling and large-scale displacement analysis. We then analyzed localized deformations related to anthropogenic activities at two different regions using S-1 InSAR time-series analysis. In the first case study, small-magnitude (mm/yr) displacement related to underground gas storage and landfill compaction in Berlin is investigated. Despite low rates of displacement, Persistent Scatterer InSAR (PSI) using an extensive collection of S-1 data reflects both the long-term trend and seasonal variations related to dynamics of gas storage in the reservoir. We estimate long-term surface uplift of up to 2 mm/yr between October 2014 and January 2017 and seasonal variations of up to 2 cm due to charge and discharge of the reservoir during summer and winter periods. An old demolishing landfill NW of Berlin was also found to be subsiding with rates as much as 8 mm/yr. The other case study is a brown coal mining area south of Leipzig. Time-series of S-1 data using the Small BAseline Subset (SBAS) approach provides new insights into mining-induced deformations in this region. Our results show rapid subsidence of up to 4 cm/yr between October 2014 and April 2017 in two active open-pit mining areas in the region.