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
Underground mining activity in the region of the Upper Silesian Coal Basin (USCB) results in ground displacements scattered on a large area. Both the locations and the velocities of the displacements depend on many factors, such as the current location of the mining front, the mining depth and system, as well as geological conditions. Although SAR interferometry techniques allow the monitoring of such ground displacements, in a regional scale (as is the case of the USCB) SAR images must be appropriately processed (from a number of frames and swaths), and this is the problem addressed in this article. The implementation of algorithms for analyzing time series allows observations of displacements in both time and space. The authors also analyze the influence of mining operations on the road infrastructure and mining waste heaps located in the area and investigate the potential for the monitoring of secondary influence (due to induced seismic tremors). As a result of these investigations, the article presents the quality of the InSAR-SBAS data and the potential for their employment in the measurements.
The article discusses techniques for interpreting satellite images, which are capable of detecting and monitoring landslip zones, and presents a research plan for the study of landslips with the use of satellite interferometry. The exceptionally longlasting and heavy rainfall that occurred in 1997 initiated more than 20,000 landslips within the Polish Carpathians. These landslips continue to pose a threat. Some of them move almost imperceptibly - slowly but continually - yet long-lasting periods of heavy rainfall can lead to catastrophe. The price can be human lives, as well as losses into the millions connected with the devastation of technical infrastructures and entire housing estates. The sheer number of landslips that occur in the Polish Carpathians makes the traditional ways of researching them insufficient. Satellite remote sensing allows capturing a large area of interest on a single photo. Many various satellites photograph the surface of the Earth using different techniques, allowing for the selection of the best-suited image type for a given application. Synthetic Aperture Radar (SAR) images are utilized in landslip studies. The images may be interpreted using the InSAR and/or PSInSAR techniques. Both methods are capable of detecting landslip zones and monitoring them in order to assess the risk of a sudden landslide. Information of this type is significant to local authorities when planning the activities necessary to protect the safety of inhabitants and the local technical infrastructure., Katarzyna Mirek., and Obsahuje bibliografii