Potential of very high resolution SAR for persistent scatterer interferometry in urban areas

This article may be used for research, teaching and private study purposes. Any substantial or systematic reproduction, redistribution , reselling , loan or sub-licensing, systematic supply or distribution in any form to anyone is expressly forbidden. The publisher does not give any warranty express or implied or make any representation that the contents will be complete or accurate or up to date. The accuracy of any instructions, formulae and drug doses should be independently verified with primary sources. The publisher shall not be liable for any loss, actions, claims, proceedings, demand or costs or damages whatsoever or howsoever caused arising directly or indirectly in connection with or arising out of the use of this material. Persistent scatterer interferometry (PSI) has matured to an established method for detection of large-scale and small-scale deformation phenomena in urban areas and of man-made infrastructure. Deformation regimes originating from oil, gas, or water extraction, storage of gas underground, CO 2 sequestration, loading of dams and dykes, and mining activities are prominent examples for investigations that have been carried out successfully applying the PSI technique to ERS or ENVISAT data stacks. Due to the sparse spatial distribution of persistent scatterers (PSs) and the moderate resolution of the mentioned satellites it has usually not been possible to track down the source of scattering in detail. The use of PSs was also opportunistic, that is, the PSI monitoring of individual buildings or specific parts of infrastructure was not always been guaranteed. This situation changes dramatically if PSI is applied to very high resolution data obtained from modern radar satellites like TerraSAR-X or COSMO-Skymed. For example, TerraSAR-X is able to deliver images with a resolution of up to 1 m in azimuth and 0.6 m in slant range when operated in the so-called high-resolution spotlight mode with 300 MHz bandwidth. This kind of data provide much more details of single objects and at the same time much higher PS densities. Compared to ERS or ENVISAT type data, the PS density can increase by factors of 100–200 on the same area. This is caused by the physical fact that at higher resolution and shorter wavelength, small scatterers (e.g., trihedrals) show higher signal-to-clutter ratio. Often, several tens to more than a hundred PSs can be found on a single large building facade or roof. Thus, individual buildings and infrastructure can be monitored in terms of structural stress and seasonal deformation, which …