The PSIG approach to persistent scatterer interferometry

This paper describes some of the key features of the Persistent Scatterer Interferometry chain of the Geomatics (PSIG) Division of CTTC. The paper firstly provides an overview of the entire PSI chain. It then focuses on the first part of the chain, which provides the input data for the estimation of the Atmospheric Phase Screen (APS). In this part, the so-called Cousin Persistent Scatterers (CPSs) are sought, which are Persistent Scatterers (PSs) characterized by a moderate spatial phase variation that ensures a correct phase unwrapping. The main output of this part of the chain is a set of correctly unwrapped and temporally ordered phases, which are computed on CPSs that cover homogeneously the area of interest. In order to do so a procedure to check the consistency of phase unwrapping is used. The paper describes the used algorithms and illustrates their performances using a set of TerraSAR-X StripMap images over the metropolitan area of Barcelona

Persistent Scatterer Interferometry analysis of ground deformation in the Po Plain (Piacenza-Reggio Emilia sector, Northern Italy): Seismo-tectonic implications

This work aims to explore the ongoing tectonic activity of structures in the outermost sector of the Northern Apennines, which represents the active leading edge of the thrust belt and is dominated by compressive deformation. We have applied the Persistent Scatterer Interferom- etry (PSI) technique to obtain new insights into the present-day deformation pattern of the frontal area of the Northern Apennine. PSI has proved to be effective in detecting surface deformation of wide regions involved in low tectonic movements. We used 34 Envisat images in descending geometry over the period of time between 2004 and 2010, performing about 300 interferometric pairs. The analysis of the velocity maps and of the PSI time-series has allowed to observe ground deformation over the sector of the Po Plain between Piacenza and Reggio Emilia. The time-series of permanent GPS stations located in the study area, validated the results of the PSI technique, showing a good correlation with the PS time-series. The PS analysis reveals the occurrence of a well-known subsidence area on the rear of the Ferrara arc, mostly connected to the exploitation of water resources. In some instances, the PS velocity pattern reveals ground uplift (with mean velocities ranging from 1 to 2.8 mm yr 121 ) above active thrust-related anticlines of the Emilia and Ferrara folds, and part of the Pede-Apennine margin. We hypothesize a correlation between the observed uplift deformation pattern and the growth of the thrust-related anticlines. As the uplift pattern corresponds to known geological features, it can be used to constrain the seismo-tectonic setting, and a working hypothesis may involve that the active Emilia and Ferrara thrust folds would be characterized by interseismic periods possibly dominated by aseismic creep

Proceedings of The HKIE Geotechnical Division 41st Annual Seminar: Adapt to Challenges, Create to Thrive

This seminar proceedings contains articles on the various research ideas of the academic community and practitioners presented at The HKIE Geotechnical Division 41st Annual Seminar (GDAS2021). GDAS2021 was jointly organized by the Geotechnical Division, The Hong Kong Institution of Engineers, & The Hong Kong Geotechnical Society on July 18th May 2021. Seminar Title: The HKIE Geotechnical Division 41st Annual SeminarSeminar Acronym: GDAS2021Seminar Date: 18 May 2021Seminar Location: Online (Virtual Mode)Seminar Organizers: Geotechnical Division, The Hong Kong Institution of Engineers, & The Hong Kong Geotechnical Society