Differential Synthetic Aperture Radar Interferometry Research Articles

Improved EMCF-SBAS Processing Chain Based on Advanced Techniques for the Noise-Filtering and Selection of Small Baseline Multi-Look DInSAR Interferograms

We present in this paper a solution to drastically improve the deformation time-series retrieval capability of the small baseline differential SAR interferometry (DInSAR) processing chain based on the cascade of the extended minimum cost flow (EMCF) phase unwrapping method and of the small baseline subset (SBAS) inversion technique. This improvement relies on the inclusion of two preprocessing steps implementing an effective noise-filtering operation and an efficient interferogram selection procedure, respectively. The former step filters out the noise affecting the phase components of a redundant set of conventional multi-look small baseline interferograms. This is achieved by solving, for each pixel, a nonlinear minimization problem based on computing the wrapped phase vector that minimizes the weighted circular variance of the phase difference between the original and noise-filtered interferograms. This technique is very easy to implement because it does not require any pixel selection step to be applied to the exploited full-resolution SAR images, and it has no need of any a priori information on the statistics of the complex-valued SAR images. The latter step, implementing the interferogram selection procedure, is carried out via a computationally efficient simulated annealing algorithm and allows identifying the optimum set of previously filtered small baseline interferograms to be used as input for the original EMCF-SBAS processing chain by maximizing the (average) coherence values. The presented results, achieved by processing three data sets collected by the ENVISAT ASAR sensor over the Abruzzi region (Central Italy), Mt. Etna volcano (South Italy), and Yellowstone Caldera (WY, USA), demonstrate the effectiveness of the proposed advanced EMCF-SBAS processing chain.

Quaternary deformation in SE Sicily: Insights into the life and cycles of forebulge fault systems

Integrated geological, geomorphological, and differential interferometry synthetic aperture radar (DInSAR) data are used to constrain the timing and modes of activity of Quaternary fault systems in the Hyblean Plateau. This area, which represents a unique natural laboratory for studying surface deformation in relation to deep slab dynamics, has grown since middle Miocene times as a doubly plunging forebulge associated with slab rollback during NW-directed subduction. Bimodal extension has produced two mutually orthogonal normal fault systems. The detailed stratigraphic record provided by synrift sediments and postrift marine terraces allowed us to define the timing of activity of an early Pleistocene, flexure-related fault system, thus constraining the duration of a typical foreland extensional tectonic event to ∼1.5 m.y. Subsequent late Quaternary to present deformation was dominated by strike-slip faulting associated with NW-oriented horizontal compression. During this latest stage, regional uplift progressively increased toward the thrust front to the NW and was accompanied by differential uplift accommodated by dip-slip components of motion along active NNW-trending faults. The general active tectonic setting of the study area, characterized by NW-oriented horizontal compression consistent with major plate convergence, and the regional uplift pattern can both be explained within the framework of intraplate shortening and foreland rebound following complete slab detachment, a major geodynamic event interpreted to have taken place at ca. 0.7 Ma in southern Italy.

Temporal Filtering of InSAR Data Using Statistical Parameters From NWP Models

Finding solutions for the mitigation of atmospheric phase delay patterns from differential synthetic aperture radar interferometry (d-InSAR) observations is currently one of the most active research topics in radar remote sensing. Recently, many studies have analyzed the performance of regional numerical weather prediction (NWP) models for this task; however, despite the significant efforts made to optimize model parameterizations, most of these studies have concluded that current regional NWPs are not able to robustly reproduce the atmospheric phase delay structures that affect SAR interferograms. Despite these previous findings, we have revisited the application of NWPs for atmospheric correction using a different analysis strategy. In contrast to earlier studies, which assessed the quality of NWP-derived phase screen data, we have studied NWPs from a statistical angle by analyzing whether they are able to provide realistic information about the statistical properties of atmospheric phase signals in d-InSAR data. We have determined that NWP forecasts can provide relevant statistical information about the atmospheric phase screen captured in d-InSAR data. Based on this, this study presents a new atmospheric phase filtering approach that is using statistical atmospheric information as a prior in order to optimize the choice of unknown filter parameters. The mathematical concept of the prior-driven filtering approach is outlined, and its implementation is explained. We have determined the performance of this new filter concept and have shown that it comes very close to a filter optimum.

Application of Surface Deformation Monitoring in Mining Area by the Fusion of InSAR and Laser Scan Data

Abstract. Differential Synthetic Aperture Radar Interferometry (D-InSAR) as a new earth observation technique has become an important tool for monitoring ground movements caused by underground coal mining. However, the low resolution and accuracy of Digital Elevation Model (DEM) cause more error value of InSAR line-of-sight(LOS) surface deformation measurement. In this paper, a couple of Radarsat-2 and a pair of TerraSAR with SRTM, GDEM and LiDAR DEM are processed respectively to reveal the subsidence basin and the results have been compared each other. It illustrate that the accuracy of D-InSAR results been better improved by the high accuracy and resolution DEM.

Evaluation of the subsidence based on dInSAR and GPS measurements near Karviná, Czech Republic

The main impacts on the landscape due to coal mining in the Czech part of the Upper Silesian basin are ground subsidence and manmade landscape changes related to the mining. Two measurement techniques were used to determine the values of subsidence; these were then compared together to verify the results obtained. The first, differential SAR interferometry (dInSAR), a remote sensing method, was applied by Gamma Remote Sensing in the frame of ESA GMES Project Terrafirma, using ALOS PALSAR data. The second was the GPS fast static method, which was provided by the Institute of Geonics AS CR. The GPS monitoring was established at a locality near Karvina in 2006. A comparison of the results is described on one subsidence depression created above a panel mined from February 2007 to May 2008. Aspects of the comparison applying to the subsidence measurements are discussed along with the advantages and disadvantages of both methods.

Radar remote sensing from space for surface deformation analysis: present and future opportunities from the new SAR sensor generation

This paper discusses, through two selected case studies based on real data, how the availability of the new generation of Synthetic Aperture Radar (SAR) sensors, characterized by reduced revisiting time and improved spatial resolution or coverage, is impacting the exploitation of Differential SAR Interferometry (DInSAR) techniques for the detection and monitoring of deformation phenomena. The presented analysis is carried out using X-band data of the COSMO-SkyMed constellation satellites, as well as C-band data acquired by the Sentinel-1A sensor; furthermore, we compare the achieved results to those based on first-generation ERS-1/2 and ENVISAT satellite data. The first case study shows how the COSMO-SkyMed X-band SAR systems open new opportunities for the detection and monitoring of deformation phenomena at the scale of a single building, even when they are characterized by a rather fast dynamic. The second experiment is based on the Sentinel-1A DInSAR measurements and permits us to envisage new scenarios for deformation analysis of very wide areas. The final discussion is devoted to summarise the lessons learned through the presented case studies and to identify the main future actions needed for a full exploitation of the surface deformation measurement capability provided by the new generation of SAR sensor.

Long term detection of water depth changes of coastal wetlands in the Yellow River Delta based on distributed scatterer interferometry

Coastal wetland ecosystems are among the most productive yet highly threatened systems in the world, and population growth and increasing economic development have resulted to extremely rapid degradation and loss of coastal wetlands. Spaceborne differential Interferometry SAR has proven a remarkable potential in wetland applications, including water level monitoring in high spatial resolution. However, due to the absence of ground observations for calibration and validation, long term monitoring of water depth, which is essential to evaluate ecosystem health of wetlands, is difficult to be estimated from spaceborne InSAR data. We present a new differential synthetic aperture radar method for temporal evolution of water depth in wetlands. The presented technique is based on distributed scatter interferogram technique in order to provide a spatially dense hydrological observation for coastal wetlands, which are characterized by high temporal decorrelation. This method adapts a strategy by forming optimum interferogram network to get a balance between maximum interferometric information preservation and computational cost reduction, and implements spatial adaptive filtering to reduce noise and enhance fringe visibility on distributed scatterers. Refined InSAR observation is tied to absolute reference frame to generate long term high resolution water level time-series using stage data. We transform water level time-series to long term observation of water depth with assistance of a dense measurement network of water depth. We present water depth time-series obtained using the data acquired from 2007 to 2010 by the ALOS satellite, which supplied significant information to evaluate ecological performance of wetland restoration in the Yellow River Delta.

A novel subsidence monitoring technique based on space-surface bistatic differential interferometry using GNSS as transmitters

Synthetic Aperture Radar Differential Interferometry (DInSAR) technique is an effective tool with large coverage and high spatial accuracy for subsidence monitoring. Nevertheless, the temporal resolution is usually poor so that rapid deformation cannot be measured due to the long revisit time of radar satellites. Bistatic SAR Differential Interferometry technique using Global Navigation Satellite System (GNSS) as illumi- nator has a shorter revisit time, whereas the measurement accuracy is constrained by low signal power, narrow bandwidth and atmospheric delay error. To cope with these problems, in this paper, we propose a novel sub- sidence monitoring technique based on Space-Surface bistatic Differential Interferometry (SS-DI) with GNSS transmitters, where two stations consist of a reference one and a measurement one that are deployed on the ground. First, we applied a space differential processing between two stations to cancel identical errors such as tropospheric and ionospheric errors etc. Then we used a long time coherent integration to improve the signal noise ratio. Subsequently, we also utilized a time differential processing to construct double differential equations with respect to unknown deformation variables. Finally, we solved the equations to obtain a highly accurate estimation of three dimension deformation. Furthermore, an SS-DI experiment using Beidou-2 as transmitters was carried out to validate the proposed method, where a high accuracy (0.01 mm) device was utilized to simu- late subsidence deformation. The experimental results reveal that the proposed method has better performance of spatial measurement accuracy of 0.53 mm compared with differential GPS method.

Assessment of soil moisture effects on L-band radar interferometry

Differential SAR interferometry, a popular technique for measuring displacements of the Earth's surface, is potentially influenced by changes in soil moisture. Different mechanisms for this impact have been proposed, but its magnitude, sign and even presence remain poorly understood. In this study the dependence of the phase, the coherence magnitude as well as the phase triplets on soil moisture was inferred empirically with regression techniques: this was done for two airborne data sets at L-band. The phase dependence was significant (at a significance level of 0.05) for more than 70% of the fields at HH polarization, its sign corresponding to an increase in optical path upon wetting, and the magnitude of the associated deformation commonly exceeding 2cm for a change in soil moisture of 20%. This trend was similar in both campaigns, whereas the prevalence of soil moisture-related decorrelation differs. These results are only consistent with a dielectric origin of the soil moisture effects, and not with soil swelling or the penetration depth hypothesis. Changes in vegetation impact the phase depending on the crop and polarization, with the vegetation influence at VV being more pronounced for the agricultural crops present in the study area.

Combination of Conventional and Advanced DInSAR to Monitor Very Fast Mining Subsidence with TerraSAR-X Data: Bytom City (Poland)

In this work, the analysis of TerraSAR-X satellite images combining both conventional and advanced Differential Synthetic Aperture Radar Interferometry (DInSAR) approaches has proven to be effective to detect and monitor fast evolving mining subsidence on urban areas in the Upper Silesian Coal Basin (Poland). This region accounts for almost three million inhabitants where mining subsidence has produced severe damage to urban structures and infrastructures in recent years. Conventional DInSAR approach was used to generate 28 differential interferograms between 5 July 2011 and 21 June 2012 identifying 31 subsidence troughs that account up to 245 mm of displacement in 54 days (equivalent to 1660 mm/year). SqueeSARTM processing yielded a very dense measurement point distribution, failing to detect faster displacements than 330 mm/year, which occur within the subsidence troughs detected with conventional DInSAR. Despite this limitation, this approach was useful to delimit stable areas where mining activities are not conducted and areas affected by residual subsidence surrounding the detected subsidence troughs. These residual subsidence mining areas are located approximately 1 km away from the 31 detected subsidence troughs and account for a subsidence rate greater than 17 mm/year on average. The validation of this methodology has been performed over Bytom City were underground mining activity produced severe damages in August 2011. Conventional DInSAR permitted to successfully map subsidence troughs between July and August 2011 that coincide spatially and temporally with the evolution of underground mining excavations, as well as with the demolition of 28 buildings of Karb district. Additionally, SqueeSARTM displacement estimates were useful to delimit an area of 8.3 km2 of Bytom city that is affected by a residual mining subsidence greater than 5 mm/year and could potentially suffer damages in the midterm. The comparison between geodetic data and SqueeSARTM for the common monitoring period yields and average absolute difference of 7 mm/year, which represents 14% of the average displacement rate measured by the geodetic benchmarks. These results demonstrate that the combined exploitation of high-resolution satellite SAR data through both conventional and advanced DInSAR techniques could be crucial to monitor fast evolving mining subsidence, which may severely impact highly populated mining areas such as the Upper Silesia Coal Basin (USCB).

Very shallow dyke intrusion and potential slope failure imaged by ground deformation: The 28 December 2014 eruption on Mount Etna

AbstractOn 28 December 2014, eruptive activity resumed at Mount Etna with fire fountain activity feeding two lava flows on the eastern and southwestern upper flanks of the volcano. Unlike all previous summit activity, this eruption produced clear deformation at the summit of the volcano. GPS displacements and Sentinel‐1A ascending interferograms were calculated in order to image the ground deformation pattern accompanying the eruption. The displacements observed by GPS depict a local ground deformation pattern, affecting only the upper part of the volcano. Despite snow cover on the summit, differential interferometry synthetic aperture radar (DInSAR) data allowed obtaining more detail on the ground deformation pattern on the upper eastern side of the volcano. Three‐dimensional GPS displacements inversion located a very shallow NE‐SW intrusion just beneath the New Southeast Crater. However, this model cannot justify all the deformation observed by DInSAR thus revealing a gravitational failure of the lava flow field.

Cosesimic liquefaction phenomena from DInSAR after the May 20, 2012 Emilia earthquake

In this paper, we have investigated the capability of Differential Interferometry Synthetic Aperture Radar (DInSAR) technique to detect the ground effects induced by liquefaction phenomena occurred during the May 20, 2012 Emilia earthquake. To this aim, a set of COSMO-SkyMed (CSK) SAR images covering the coseismic phase has been used. The detected surface effects have been related to liquefaction of deep sandy layers. Thanks to the geological/geotechnical data in the area and a liquefaction susceptibility analysis of the subsoil, it has been identified a sandy layer between 9 and 13 m in deep, which probably liquefied during the earthquake. The estimated vertical displacements due to liquefaction are comparable with the values measured by DInSAR.

A User-Oriented Methodology for DInSAR Time Series Analysis and Interpretation: Landslides and Subsidence Case Studies

Recent advances in multi-temporal Differential Synthetic Aperture Radar (SAR) Interferometry (DInSAR) have greatly improved our capability to monitor geological processes. Ground motion studies using DInSAR require both the availability of good quality input data and rigorous approaches to exploit the retrieved Time Series (TS) at their full potential. In this work we present a methodology for DInSAR TS analysis, with particular focus on landslides and subsidence phenomena. The proposed methodology consists of three main steps: (1) pre-processing, i.e., assessment of a SAR Dataset Quality Index (SDQI) (2) post-processing, i.e., application of empirical/stochastic methods to improve the TS quality, and (3) trend analysis, i.e., comparative implementation of methodologies for automatic TS analysis. Tests were carried out on TS datasets retrieved from processing of SAR imagery acquired by different radar sensors (i.e., ERS-1/2 SAR, RADARSAT-1, ENVISAT ASAR, ALOS PALSAR, TerraSAR-X, COSMO-SkyMed) using advanced DInSAR techniques (i.e., SqueeSAR™, PSInSAR™, SPN and SBAS). The obtained values of SDQI are discussed against the technical parameters of each data stack (e.g., radar band, number of SAR scenes, temporal coverage, revisiting time), the retrieved coverage of the DInSAR results, and the constraints related to the characterization of the investigated geological processes. Empirical and stochastic approaches were used to demonstrate how the quality of the TS can be improved after the SAR processing, and examples are discussed to mitigate phase unwrapping errors, and remove regional trends, noise and anomalies. Performance assessment of recently developed methods of trend analysis (i.e., PS-Time, Deviation Index and velocity TS) was conducted on two selected study areas in Northern Italy affected by land subsidence and landslides. Results show that the automatic detection of motion trends enhances the interpretation of DInSAR data, since it provides an objective picture of the deformation behaviour recorded through TS and therefore contributes to the understanding of the on-going geological processes.

Coseismic liquefaction phenomenon analysis by COSMO-SkyMed: 2012 Emilia (Italy) earthquake

The liquefaction phenomenon that occurred in the coseismic phase of the May 20, 2012 Emilia (Italy) earthquake (ML 5.9) is investigated. It was induced by the water pressure increase in the buried and confined sand layers. The level-ground liquefaction was the result of a chaotic ground oscillation caused by the earthquake shaking and the observed failures were due to the upward water flow caused by the excess of pore pressures. We exploited the capability of the differential synthetic aperture radar interferometry (DInSAR) technique to detect soil liquefactions and estimate their surface displacements, as well as the high sensitivity to surface changes of complex coherence, SAR backscattering and intensity correlation. To this aim, a set of four COSMO-SkyMed X-band SAR images, covering the period April 1–June 6, 2012, was used. Geological–geotechnical analysis was also performed in order to ascertain if the detected SAR-based surface effects could be due to the compaction induced by liquefaction of deep sandy layers. In this regards, the results obtained from 13 electrical cone penetrometer tests show the presence of a fine to medium sandy layer at depths, ranging between 9 and 13m, which probably liquefied during the earthquake, inducing vertical displacements between 3 and 16cm. The quantitative results from geological–geotechnical analysis and the surface punctual effects measured by DInSAR are in good agreement, even if some differences are present, probably ascribable to the local thickness and depth variability of the sandy layer, or to lack of deformation detection due to DInSAR decorrelation. The adopted approach permitted us to define the extent of the areas that underwent liquefaction and to quantify the local subsidence related to these phenomena. The latter achievement provides useful information that must be considered in engineering practices, in terms of expected vertical deformations.

Surface displacements of the 2014 Cephalonia (Greece) earthquake using high resolution SAR interferometry

The island of Cephalonia (Western Greece), was struck by two strong seismic events, with magnitudes Mw = 6.0 and Mw = 5.9 which occurred on Jan. 26, 2014 and Feb. 3, 2014 respectively. The first event was located near Argostoli’s village, whereas the second one was located at the north part of Livadi village. These two strong seismic events were followed by smaller aftershocks provoking extensive crustal movements and structural damage effects. Differential Synthetic Aperture Radar Interferometry (DInSAR) is a powerful remote sensing tool for ground motion monitoring. Since the last two decades, DInSAR is widely used in a variety of applications including natural hazards such as earthquakes. In 2007, a high resolution X-band satellite namely TerraSAR-X was launched. Due to its short revisit cycle of 11 days and its short wavelength, it has a good potential to capture faster surface movements. This study refers to the application of the DInSAR using TerraSAR-X strip map data to monitor the co- and post-seismic surface deformation caused by the second seismic event. Using DInSAR methodology, three differential interferograms were calculated showing the displacement trend of the region, before and after the earthquake. Results demonstrate that the main part of the island shows stability to low uplift whereas in the western part a significant deformation pattern is observed. The findings permit a better understanding and identification of the local tectonic setting of the study area and the investigation of the reasons that some settlements were strongly affected by this seismic activity.

The analysis of vertical displacements in Upper Silesian Coal Basin area using DInSAR and PSInSAR methods

The main goal of this study is an analysis of vertical displacements in Upper Silesian Coal Basin (USCB) using two satellite radar interferometry methods: Differential Interferometry Synthetic Aperture Radar (DInSAR) and Persistent Scatterer Interferometric Synthetic Aperture Radar (PSInSAR) (Ferretti et al. 2007). To detect ground deformations using the PSInSAR method many satellite images (even tens) are needed, while using the DInSAR method, a pair of satellite images is needed. Satellite images are provided inter alia by European Space Agency and were obtained between 1990-2001 (PSInSAR) and 1996-2001 (DInSAR) by ERS-2 satellite. The USCB is located in south-western Poland and is highly industrialized and densely inhabited region, because of the presence of many active underground stone coal mines. Vertical displacements presented in work are conducted by underground mining exploitation and neotectonic movements. In the main, the DInSAR method allows to detect big (a few or several centimeters) and intensive (formed in a few days, 35-140 days) vertical displacements on a big area in the same time. The PSInSAR method in the main allows to detect small and permanent vertical displacements (Leśniak & Porzycka 2008), which are correlated with neotectonic movements. It is noteworthy that results obtained using the PSInSAR method have low coherence in the areas of vertical displacements detected by using the DInSAR method. Big and intensive vertical displacements are not detected while using the PSInSAR method. Only using both methods (DInSAR and PSInSAR) allows to generate a complex map of vertical displacements, which is essential for the realization of local zoning plans in the USCB area. Obtained in this work map of vertical displacements is collated with: (1) seismic data from Glowny Instytut Geologiczny (GIG), (2) locations of mines in the USCB, (3) borders of coal deposits, (4) tectonics map (Jureczka & Kotas 1995), (5) mining extraction data from Kompania Weglowa S.A.

Polarimetric Optimization of Temporal Sublook Coherence for DInSAR Applications

The application of differential synthetic aperture radar interferometry (DInSAR) techniques has been traditionally limited to the single-polarimetric case. The launch of satellites with polarimetric capabilities has triggered the synergy between polarimetric and interferometric algorithms, leading to a significant improvement in final DInSAR products. During the last years, the different polarimetric optimization techniques available have been successfully applied to the so-called classical phase quality estimators, i.e., the coherence and the amplitude dispersion estimators. In this context, a new estimator to evaluate the pixels' phase quality, referred to as temporal sublook coherence (TSC), has recently demonstrated to provide promising results in DInSAR applications. The nature of this estimator, which is based on exploiting the spectral properties of pointlike scatterers through the coherence evaluation of different sublooks of the image spectrum, allows its adaptation to the existing polarimetric optimization methods. This letter presents the benefits of extending the TSC estimator to work with fully polarimetric data. For this purpose, a fully polarimetric data set consisting of ten X-band ground-based SAR (GB-SAR) images is employed. The final DInSAR results obtained by means of TSC polarimetric optimization are compared with the ones obtained with its classical single-polarimetric approach, achieving up to more than a twofold increase in the pixels' density.

The Limitation of Maximum Detectable Deformation Resolved by Differential SAR Interferometry

Differential SAR interferometry (DInSAR) provides a new tool for detecting deformation in the line of sight (LOS) of Earth’s surface. However, not all deformation can be detected. In order to get the maximum detectable deformation, the decorrelation in terms of coherence and deformation has been proposed. The influence of deformation on decorrelation is then discussed for both registering drifted pixels method and registering fixed method. Based on aforementioned analysis, the limitation of maximum detectable deformation has been derived for these two cases. Furthermore, computer simulations are carried out to confirm the detectable deformation discussion as the coherence equals to 0.5. The result of registering drifted pixels method shows that the detectable limitation does not only depend on coherence but also on other factors such as beamwidth. The result of registering fixed pixels method, however, shows that the detectable deformation and baseline have an inverse relationship.

DInSAR 멀티 트랙 시계열 기법을 이용한 알라스카 시구암 화산의 2차원 지표변위 관측

Small BAseline Subset (SBAS) technique using multi master interferograms can be effective to detect surface deformation in forest area. In this paper, The analysis reveals area of 2-dimension surface deformation at Seguam Island in Aleutian Arc., Alaska. We acquired ERS-1/2 data from track 201 and 473 datasets on Seguam Island from 1992 to 2008. This study analyze surface deformation applying Differential Interferometry Synthetic Aperture Radar (DInSAR) and SBAS time series method using two adjacent tracks. As a results, it was calculated that subsidence -1~2 cm in LOS direction and - 2~3 cm in vertical direction. The horizontal direction was repeated contraction and expansion. The observation of 2-dimension displacements explained the volcanic activity on Seguam island. Also, it is believed to be used for basic data to estimate movements of magma source.

Landslide Kinematical Analysis through Inverse Numerical Modelling and Differential SAR Interferometry

The aim of this paper is to propose a methodology to perform inverse numerical modelling of slow landslides that combines the potentialities of both numerical approaches and well-known remote-sensing satellite techniques. In particular, through an optimization procedure based on a genetic algorithm, we minimize, with respect to a proper penalty function, the difference between the modelled displacement field and differential synthetic aperture radar interferometry (DInSAR) deformation time series. The proposed methodology allows us to automatically search for the physical parameters that characterize the landslide behaviour. To validate the presented approach, we focus our analysis on the slow Ivancich landslide (Assisi, central Italy). The kinematical evolution of the unstable slope is investigated via long-term DInSAR analysis, by exploiting about 20 years of ERS-1/2 and ENVISAT satellite acquisitions. The landslide is driven by the presence of a shear band, whose behaviour is simulated through a two-dimensional time-dependent finite element model, in two different physical scenarios, i.e. Newtonian viscous flow and a deviatoric creep model. Comparison between the model results and DInSAR measurements reveals that the deviatoric creep model is more suitable to describe the kinematical evolution of the landslide. This finding is also confirmed by comparing the model results with the available independent inclinometer measurements. Our analysis emphasizes that integration of different data, within inverse numerical models, allows deep investigation of the kinematical behaviour of slow active landslides and discrimination of the driving forces that govern their deformation processes.