SNAP2DQuake: an implemented and automatic tool of ESA SNAP's Python module for DInSAR technique on ground deformation estimation from Sentinel-1 data

Differential SAR Interferometry (DInSAR) is a largely exploited technique applicable to different case studies involving ground deformation on Earth. A key application is the detection of the effects promoted by large earthquakes, comprising detailed variations in ground deformations at large an local scales. Since one limit of this technique relies on the costs that may be present for the access of some satellitary imagery or software licenses for the data processing, this latter problematic can be solved with the adoption of an alternative processing performed via scripts. In this work, an automatic open-source implemented Python script (Snap2DQuake) based on the “snappy” module by SNAP software 9.0.8 (ESA) for the processing of Sentinel-1 images is presented. The main feature of the script is the reproduction of all the operators contained in SNAP software using the tools of “snappy”, in order to avoid some issues that can occurr using the software, and to build a complete, simple and automatic workflow to obtain LOS deformation maps and the derived Horizontal (E-W) and Vertical deformation maps. The automatization of the processing makes Snap2DQuake easy to use and suitable with basic users of programming. The proposed tool has been tested on two case studies referred two different tectonic contexts: the Mw 6.4 Petrinja earthquake (Croatia, December 2020) and the Mw 5.7 to Mw 6.3 seismic sequence occured near Tyrnavós (Greece, March 2021). The output maps of Snap2DQuake, in agreement with field observations and previous work, furnish new insights insights into the deformation pattern linked to earthquakes, demonstrating the reliability of Snap2DQuake as an alternative tool for users working on different applications, even with basic coding skills.