Displacement monitoring in airport runways by persistent scatterers SAR interferometry

Deformations monitoring in airport runways and the surrounding areas is crucial, especially in case of low-bearing capacity subgrades, such as the clayey subgrade soils. An effective monitoring of the infrastructure asset allows to secure the highest necessary standards in terms of the operational and safety requirements. Amongst the emerging remote sensing techniques for transport infrastructures monitoring, the Persistent Scatterers Interferometry (PSI) technique has proven effective for the evaluation of the ground deformations. However, its use for certain demanding applications, such a as the assessment of millimetric differential deformations in airport runways, is still considered as an open issue for future developments. In this study, a time-series analysis of COSMO-SkyMed satellite images acquired from January 2015 to April 2019 is carried out by employing the PSI technique. The aim is to retrieve the mean deformation velocity and time series of the surface deformations occurring in airport runways. The technique is applied to Runway 3 at the “Leonardo da Vinci” International Airport in Rome, Italy. The proposed PSI technique is then validated by way of comparison with the deformation outcomes obtained on the runway by traditional topographic levelling over the same time span. The results of this study clearly demonstrate the efficiency and the accuracy of the applied PSI technique for the assessment of deformations in airport runways

Satellite remote sensing and non-destructive testing methods for transport infrastructure monitoring: advances, challenges and perspectives

High temporal frequency monitoring of transport infrastructure is crucial to prioritise mainte-nance and prevent major service disruption or structural failures. Ground-based non-destructive testing (NDT) methods have been successfully applied for decades, reaching very high standards for data quality and accuracy. However, routine campaigns and long inspection times are re-quired for data collection and their implementation into reliable infrastructure management systems (IMSs). On the other hand, satellite remote sensing techniques, such as the Mul-ti-Temporal Interferometric Synthetic Aperture Radar (MT-InSAR) method, have proven effective in monitoring ground displacements of transport infrastructure (roads, railways and airfields) with a much higher temporal frequency of investigation and the capability to cover wider areas. Nevertheless, the integration of information from i) satellite remote sensing and ii) ground-based NDT methods is still a subject to be fully explored in civil engineering. This paper aims to review significant stand-alone and combined applications in these two areas of endeavour for transport infrastructure monitoring. Recent advances, main challenges and future perspectives arising from their mutual integration are also discussed

Urban Deformation Monitoring using Persistent Scatterer Interferometry and SAR tomography

This book focuses on remote sensing for urban deformation monitoring. In particular, it highlights how deformation monitoring in urban areas can be carried out using Persistent Scatterer Interferometry (PSI) and Synthetic Aperture Radar (SAR) Tomography (TomoSAR). Several contributions show the capabilities of Interferometric SAR (InSAR) and PSI techniques for urban deformation monitoring. Some of them show the advantages of TomoSAR in un-mixing multiple scatterers for urban mapping and monitoring. This book is dedicated to the technical and scientific community interested in urban applications. It is useful for choosing the appropriate technique and gaining an assessment of the expected performance. The book will also be useful to researchers, as it provides information on the state-of-the-art and new trends in this fiel

Geodynamic monitoring of development of a karst on the basis of georadar sounding

The questions of practical application of georadar sounding for the detailed studying of development of a karst were considered in the article. The importance of the problem being solved for the planning of construction and further operation of industrial facilities in karst limestone areas is emphasized. In the last case, the geodynamic control of karst zones is necessary, as operation of objects in these zones is economi

Testing sentinel-1 SAR interferometry data for airport runway monitoring: a geostatistical analysis

Multi-Temporal Interferometric Synthetic Aperture Radar (MT-InSAR) techniques are gaining momentum in the assessment and health monitoring of infrastructure assets. Amongst others, the Persistent Scatterers Interferometry (PSI) technique has proven to be viable for the long-term evaluation of ground scatterers. However, its effectiveness as a routine tool for certain critical application areas, such as the assessment of millimetre-scale differential displacements in airport runways, is still debated. This research aims to demonstrate the viability of using medium-resolution Copernicus ESA Sentinel-1A (C-Band) SAR products and their contribution to improve current maintenance strategies in case of localised foundation settlements in airport runways. To this purpose, “Runway n.3” of the “Leonardo Da Vinci International Airport” in Fiumicino, Rome, Italy was investigated as an explanatory case study, in view of historical geotechnical settlements affecting the runway area. In this context, a geostatistical study is developed for the exploratory spatial data analysis and the interpolation of the Sentinel-1A SAR data. The geostatistical analysis provided ample information on the spatial continuity of the Sentinel 1 data in comparison with the high-resolution COSMO-SkyMed data and the ground-based topographic levelling data. Furthermore, a comparison between the PSI outcomes from the Sentinel-1A SAR data—interpolated through Ordinary Kriging—and the ground-truth topographic levelling data demonstrated the high accuracy of the Sentinel 1 data. This is proven by the high values of the correlation coefficient (r = 0.94), the multiple R-squared coefficient (R2 = 0.88) and the Slope value (0.96). The results of this study clearly support the effectiveness of using Sentinel-1A SAR data as a continuous and long-term routine monitoring tool for millimetre-scale displacements in airport runways, paving the way for the development of more efficient and sustainable maintenance strategies for inclusion in next generation Airport Pavement Management Systems (APMSs)

An investigation of ongoing displacements of active faults in the Gobi desert using persistent scatterer interferometric synthetic aperture radar technique to support the permanent disposal of high-level waste in Beishan, China

This research demonstrated the application of PSInSAR method in identifying and characterising the micro-displacements along active faults in Beishan to support the selection of GDF host rock. This research first distinguishes and separates the tectonic induced and non-tectonic induced deformation within three study areas at Suanjingzi, Jiujing and Xinchang. Through the application of coherence change detection, it found the granite outcrop areas characterised by high coherence provide more robust results of tectonic activity. The Quaternary sediments covered areas which are characterised by low coherence usually show higher deformation rates due to the impacts of erosion and deposition. The tectonic induced displacements generally range from -0.4 to 0.4 mma-1 and are dominated by fault bound tectonic movements. As a part of wrench faut zone, Beishan is impacted by a NE-SW trended maximum in situ compressive stress field (σ1). To correlate the visible valleys, gullies, or cracks in Google Earth imagery with the SAR image deformation discontinuities, this study mapped and characterised more than 40 active faults in the three study areas, these include (1) the NE-SW trended sinistral strike-slip faults triggered by extension and (2) the NW-SE/W-E trended reverse faults triggered by maximum compression. The fault activity is characterised by subtle (minor) displacement rate value difference between the two sides of the fault plane. This research successfully improved the understanding of local structural geology and provided moderate guidance for the selection of HLW disposal sites in China. It was indicated that Xinchang has the highest tectonic stability, and this is then followed by Jiujing and Suanjingzi. This kind of displacement rate difference is possible due to the angle difference towards the Sanweishan Fault Zone. To trace and characterise the undiscovered active fault planes, the PSInSAR approach also benefits the prediction of earthquake by improving the positioning of the potential epicentres.Open Acces

Integration of InSAR and GPR techniques for monitoring transition areas in railway bridges

This paper reports the integration of the Ground Penetrating Radar (GPR) and the Interferometric Synthetic Aperture Radar (InSAR) techniques for the monitoring of the rail-abutment transition area in railway bridges. To this purpose, an experimental campaign was conducted on a rail truss bridge located in Puglia, Southern Italy. On one hand, GPR was used to obtain structural details of the subsurface (thickness of the ballasted layer, position of the sleepers, presence of clay/humidity spots) and to identify potential construction-related issues. Parallel to this, InSAR analyses were mainly addressed to monitor subsidence at the rail-abutment transition area. Outcomes of this investigation outlined presence of subsidence at both the areas of transition and have proven the proposed integrated approach as viable to achieve a more comprehensive assessment of the structural integrity of railway bridges

Deformation Monitoring and Analysis of the Geological Environment of Pudong International Airport with Persistent Scatterer SAR Interferometry

Many coastal cities have undertaken reclamation projects to satisfy the land demands of rapid urbanization. However, the foundations of reclaimed land are susceptible to settlement and can have undesirable environmental impacts that could adversely affect these dense, populated areas. In the case of international airports built on reclaimed areas especially, regional-scale deformation must be monitored to ensure operational security for public safety. Persistent Scatterer SAR Interferometry (PSI) technology has proven to be an effective tool to detect ground deformation in urban areas. However, it is still a challenge to apply PSI to effectively monitor settlement at airports built on newly developed coastal reclamation areas because of the scarcity of identifiable targets. Moreover, additional issues arise as the complicated deformation patterns associated with the underlying geological conditions make it difficult to interpret InSAR-derived results. In this study, a time-series analysis of a high-resolution TerraSAR-X satellite image stack acquired from September 2011 to October 2012 was performed by employing a modified PSI technique to retrieve the mean deformation velocity and time series of surface deformation at Pudong International Airport. Qualitative evaluation of spatial distribution and temporal evolution of deformation was conducted by joint analyses of deformation measurements and local geological data. Detailed analysis of various driving forces for deformation patterns confirmed that the results of deformation monitoring obtained by PSI are reliable and consistent with that of local geological surveys. Since the factors responsible for the subsidence within the airport are still at play, ongoing and routine deformation monitoring is warranted