Interferometric SAR monitoring of the Vallcebre landslide (Spain) using corner reflectors

Abstract

Abstract. This paper describes the deformation monitoring of the Vallcebre landslide (Eastern Pyrenees, Spain) using the Differential Interferometric Synthetic Aperture Radar (DInSAR) technique and corner reflectors (CRs). The fundamental aspects of this satellite-based deformation monitoring technique are described to provide the key elements needed to fully understand and correctly interpret its results. Several technical and logistic aspects related to the use of CRs are addressed including an analysis of the suitability of DInSAR data to monitor a specific landslide, a discussion on the choice of the type of CRs, suggestions for the installation of CRs and a description of the design of a CR network. This is followed by the description of the DInSAR data analysis procedure required to derive deformation estimates starting from the main observables of the procedure, i.e., the interferometric phases. The main observation equation is analysed, discussing the role of each phase component. A detailed discussion is devoted to the phase unwrapping problem, which has a direct impact on the deformation monitoring capability. Finally, the performance of CRs for monitoring ground displacements has been tested in the Vallcebre landslide (Eastern Pyrenees, Spain). Two different periods, which provide interesting results to monitor over time the kinematics of different parts of the considered landslide unit, are analysed and described.

Monitoring soil creep landsliding in an urban area using persistent scatterer interferometry (El Papiol, Catalonia, Spain)

“…We must underline that this map lacks information for the nonurbanised areas, as a consequence of the aforementioned PSI limitation. This limitation could be overcome using conventional techniques or performing PSI using corner reflectors (see Crosetto et al (2013)). …”

“…As for landslide monitoring, there are several PSI works that cover broad areas; see Righini et al (2012), Strozzi et al (2013) and Wasowski and Bovenga (2014). In addition, there are several studies focused on single large landslides; see Fruneau et al (1996), Colesanti et al (2003), Hilley et al (2004), Crosetto et al (2013) and Tofani et al (2014). Most of these studies focus on displacements of large landslides for which previous geomorphologic analyses are available.…”

A technical review on persistent scatterer interferometry

“…If PS density is still low over a target area, artificial corner reflectors can be used to provide strong responses in the SAR image so as to achieve a good interferometric phases for the estimation of the deformation and assess the performance of DInSAR and PSI [13][14][15]. Technical aspects on artificial corner reflectors in DIn-SAR are described in Ye et al [16] and Crosetto et al [17]. This technique has been applied to PSI [18,19].…”

Preliminary results from active landslide monitoring using multidisciplinary surveys

“…PSI using ERS-1/2 and Envisat data has been applied for landslide monitoring in the Italian Alps (Del Ventisette, Righini, Moretti, & Casagli, 2014). The same approach was exploited different SAR data and the results were associated with GNSS data (Bovenga, Refice, Pasquariello, Nitti, & Nutricato, 2014;Colesanti & Wasowski, 2006;Crosetto et al, 2013). The PSI technique was also combined with in situ geological and geomorphological evidences as well as with standard geodetic methods, yielding to precisely update ground movements in high instability of Gimigliano area in Italy and a respective area in Lithuania (Bianchini, Cigna, Del Ventisette, Moretti, & Casagli, 2013;Čyžienė, Minkevičius, Mikulėnas, & Satkūnas, 2012).…”