Multi-temporal L-band SAR interferometry confirms C-band spatial patterns of subsidence in the ancient Wieliczka Salt Mine (UNESCO Heritage Site, Poland)

This work presents first results of interferometric processing of ALOS PALSAR Single Look Complex SAR images (Fine Beam Mode), concerning ground deformations in the Wieliczka Salt Mine area, a few km from Cracow, Poland. It follows a recent Persistent Scatterers SAR Interferometry (PSI) analysis on this area, obtained by processing several tens of ERS satellite images covering the period 1992-2000. ERS results revealed the presence of a few kilometres long, slowly subsiding zone corresponding very well to the extent of the underground salt mine. The present work aims to extend the analysis by exploiting ALOS-PALSAR data especially for the rural areas, which neighbour the salt mine but lack PS in C-band, relying on the lower sensitivity to temporal decorrelation of L-band w.r.t. C-band radar data. This work shows and compares ERS and PALSAR (Fine Beam) ground displacement patterns detected over the Wieliczka Salt Mine area through the application of multi-temporal interferometric techniques.