Detection of ground subsidence in the city of Lisbon: Comparison of InSAR and topographic measurements

In this work we present the results of an experiment aiming to measure a ground subsidence in the city of Lisbon, Portugal, possibly related to works for the building of the city´s subway infrastructure. A time series of 46 ERS SAR images, acquired between May 1995 and January 2001, is interferometrically processed using the Persistent Scatterers (PS) technique and terrain deformation velocities estimated at the location of PS. The interferometric SAR (InSAR) estimates are compared to topographic measurements of terrain subsidence carried out in 1976, 1996 and 2010.