A Comparative Analysis of Different Dinsar Approaches to Filter Out Atmospheric Phase Artifacts in Active Volcano Scenarioes Characterized by High Topography Surfaces

We present in this paper a comparative analysis focused on the estimation and removal of the Atmospheric Phase Screen (APS) from DInSAR deformation measurements relevant to volcanic areas characterized by significant displacements and topography. These are scenarios where it is often difficult to separate the interferometric phase component due to atmospheric artifacts from the one related to the actual ground deformation. In particular, we investigate the APS correction performance achieved by applying two different approaches: i) the first relying on the exploitation of the external meteorological ERA-5 data, ii) the second based on filtering out atmospheric contributions from the DInSAR time series by exploiting their statistical properties both in space and in time. For the experimental analysis we analyze very large Sentinel-1 datasets acquired over two volcanic areas particularly challenging from the point of view of the APS estimation: La Palma island (Canary, Spain), focusing on the last eruption occurred on 19 September 2021, and Mt. Etna (Sicily, Italy).