COSMO-SkyMed vs RADARSAT-2 for Monitoring Natural and Anthropogenic Components of the Land Movements in Venice

Abstract

We present the result of a test aimed at evaluating the capability of RADARSAT-2 and COSMO-SkyMed to map the natural subsidence and ground movements induced by anthropogenic activities in the historical center of Venice. Firstly, ground movements have been retrieved at quite long- and short-term by the Persistent Scattered Interferometry (PSI) on 2008-2015 RADARSAT-2 and 2013-2015 COSMO-SkyMed image stacks, respectively. Secondly, PSI has been calibrated at regional scale using the records of permanent GPS stations. Thirdly, considering that over the last two decades “in the historical center of Venice” natural land movements are primarily ascribed to long-term processes, and those induced by human activities act at short-term, we have properly resampled 83-month RADARSAT-2 C-band and 27-month COSMO-SkyMed X-band interferometric products by a common grid and processed the outcome to estimate the two components of the displacements. Results show that the average natural subsidence is generally in the range of 0.9 – 1.1 mm/yr and the anthropogenic ground movements are up to 2 mm/yr.