Persistent Scatterer Interferometry (PSI), a remote sensing technique, is used for detecting surface deformation in the cities of Prague and Ostrava. PSI is able to detect vertical movements with an accuracy of less than 1 mm for a long time series of the SAR data, but the maximum detectable rate of movement is only a few centimetres per year. This technique is quite suitable for detecting recent movements in most Prague localities. On the other hand, in Ostrava and its surroundings, affected by undermining, where subsidences (1992-2006) amount to decimetres per year, movements cannot be fully detected by the PSInSAR technique. The paper presents results of analysing PSI data for two localities in Prague and one locality in the Ostrava areas. The localities are strictly situated in built-up areas with many suitable reflectors. Data from the ERS-1/2 and ENVISAT satellites covering a 13-year period for the Prague (1992-2005) and a 14-year period for the Ostrava (1992-2006) area were used. Annual movement velocities and time-series of reflectors were determined. At these three localities, where different types of movements were identified, the application and possible limitations of PSI in urban areas are shown., Pavel Kadlečík, Vladimír Schenk, Zuzana Seidlová and Zdeňka Schenková., and Obsahuje bibliografii
Secondary deformations are ground movements occurring in areas of ceased underground mining. These are associated with delayed readjustment of rock mass resulting in subsidence, discontinuous deformations (sinks, cracks, etc.) due to destruction of underground, usually shallow, workings, and elevation of ground surface in response of rock mass to rising groundwater levels following the end of mine water drainage. Comparative analysis of secondary deformations in two former mining areas in the first period after cessation of underground hard coal mining is the subject of this study. We used ERS-1/2 and Envisat satellite radar interferometry data processed with PSInSAR technique and GIS to map vertical (in satellite’s line of sight, LOS) movements of the surface and analyse them in relation to location of coal fields and underground water table rise. In the study, two areas have been compared, the Ostrava city in the Czech part of the Upper Silesian Basin and the Wałbrzych Coal Basin in Poland. The results of analyses based on the results of PSInSAR processing between 1995 and 2000 for the Wałbrzych site indicate uplift (up to +12 mm/year) in closed parts of coal fields and subsidence (up to -8 mm/year) in areas of declining mining. Results of PSInSAR analysis over the Ostrava site indicate decaying subsidence after mine closures in the rate of up to -6 mm/year during 1995-2000. Residual subsidence and gentle uplift have been partly identified at surroundings of closed mines in Ostrava from 2003-2010 Envisat data. In Wałbrzych gentle elevation has been determined from 2002 to 2009 in areas previously subsiding. and Blachowski Jan, Jiránková Eva, Lazecký Milan, Kadlečík Pavel, Milczarek Wojciech.