COSMO-SkyMed Satellites Research Articles

Enhancing Landslide Prediction Through Advanced Transformer-Based Models: Integrating SAR Imagery and Environmental Data

Landslides, a significant natural hazard driven predominantly by rainfall infiltration, pose a continuous threat to the terrain, buildings, and ecosystem of Caiazzo, located in southern Italy (Caserta). This research undertakes a novel approach to predict and understand the complex patterns of landslide deformations in this region. Our study leverages the advanced capabilities of COSMO-SkyMed satellite imagery, integrating a comprehensive dataset that includes factors such as elevation, slope, Topographic Wetness Index, Stream Power Index, geology, flow direction, curvature, Normalized Difference Vegetation Index, and several other relevant indices. We employ Transformer-based models, renowned for their effectiveness in capturing long-range dependencies within sequential data. The Transformer models in our study are adept at analyzing the temporal sequences of environmental factors and their intricate interactions, thereby offering a more nuanced understanding of the temporal patterns leading to landslides. These Transformer models are designed to process the entire sequence of satellite data obtained by the Coherent Pixels - Temporal Phase Coherence within the SUBSOFT package to ensure data integrity and precision, encompassing 132 images in ascending geometry and 143 in descending geometry, spanning from 2013 to 2021. By doing so, they efficiently identify critical patterns and dependencies over time, such as the interplay between rainfall events and subsequent soil and vegetation changes. The models are fine-tuned to our specific dataset, ensuring high precision and accuracy in landslide deformation prediction. Our evaluation metrics, including Mean Absolute Error, Root Mean Square Error, and R^2 score, demonstrate the superior performance of the Transformer-based approach, with significant improvements over the conventional Deep Learning model. The visual correlation of our predictions with actual landslide occurrences further corroborates the effectiveness of this method. This transformative approach not only enhances our understanding and predictive capability for landslides in Caiazzo but also sets a benchmark for landslide prediction in geologically vulnerable regions worldwide.

Bayesian Data Fusion for Enhanced Monitoring of Bridge Displacements Using Satellite InSAR and Topographic Techniques

This paper investigates the effectiveness of satellite Interferometric Synthetic Aperture Radar (InSAR) technology to remotely monitor the structural health of road bridges and detect possible unexpected behaviours. The study is based on an Italian multi-span prestressed concrete bridge and a dataset of eight years of X-band SAR images collected by the COSMO-SkyMed satellite constellation. The method implemented for this study is as follows. First, SAR images are analysed using the Multi-Temporal InSAR technique to extract displacement time series of reflective targets on the bridge decks. Then, the extracted displacements are interpreted to validate their consistency with the bridge's expected responses to environmental loads, such as air temperature and river water flow variations, and detect possible unexpected behaviours. Eventually, the correlation with the air temperature is investigated to identify different bridge spans based only on monitoring data. The findings from this study advance the knowledge on using satellite InSAR-based monitoring for early detection of anomalous bridge behaviours on a large scale, providing valuable insights for the maintenance and safety of critical infrastructure.

Damage Assessment Through the Use of SBAS-DInsar Data: An Application to the “Vittorino da Feltre” Masonry School Building in Rome

ABSTRACT The detection and monitoring of deformation patterns induced by causes of various nature is fundamental to prevent and mitigate the associated risk. To this aim, one of the most innovative, non-invasive monitoring approaches is based on the use of satellite radar images through the advanced multi-temporal Differential Interferometry Synthetic Aperture Radar (DInSAR) technique, which is able to detect deformations induced by slowly evolving phenomena. In this work, the multi-temporal DInSAR technique referred to as full resolution SBAS approach is exploited for the monitoring of the ground deformations and their effects on the “Vittorino da Feltre” school building located in the city of Rome (Italy), which is undergoing a retrofitting project. The displacement measurements were obtained by using the COSMO-SkyMed satellite dataset related to the city of Rome during the 2011–2019 time interval, processed with full resolution Small. The damage progression during the last years has been evaluated by comparing a recent survey of the structural damage with the previously available ones. An integration of SAR-derived data and outcomes of the on-site damage surveys is presented, aimed to perform a damage assessment of the structure using literature scales of damage.

Outlet glacier flow response to surface melt: based on analysis of a high-resolution satellite data set

The dynamics of the Greenland Ice Sheet are affected by surface meltwater reaching the base of the ice, altering ice contact with the bedrock. Lack of understanding of this evolution hampers the ability to predict the effects of increasing temperatures on the Greenland Ice Sheet mass balance. Here we present a unique high-resolution study of ice velocity response to surface melting based on data from a COSMO-SkyMed satellite campaign over Upernavik Isstrøm (Northwest Greenland) for two months around the end of the 2014 melt season. We show that the velocity variations, due to both short-term (days) and seasonal variations in surface melt rates, are increasing in relative strength farther from the glacier terminus. Furthermore, we observe how ice dynamic response to frontal retreat, reaching several kilometres inland, can obscure the meltwater-induced velocity change close to the terminus. Future studies should consider the flow velocity dependence on the distance to the terminus, and local geometry, to distinguish subglacial hydrologic system changes from frontal processes and local basal conditions.

A Complete Meteo/Hydro/Hydraulic Chain Application to Support Early Warning and Monitoring Systems: The Apollo Medicane Use Case

Because of the ongoing changing climate, extreme rainfall events’ frequency at the global scale is expected to increase, thus resulting in high social and economic impacts. A Meteo/Hydro/Hydraulic forecasting chain combining heterogeneous observational data sources is a crucial component for an Early Warning System and is a fundamental asset for Civil Protection Authorities to correctly predict these events, their effects, and put in place anticipatory actions. During the last week of October 2021 an intense Mediterranean hurricane (Apollo) affected many Mediterranean countries (Tunisia, Algeria, Malta, and Italy) with a death toll of seven people. The CIMA Meteo/Hydro/Hydraulic forecasting chain, including the WRF model, the hydrological model Continuum, the automatic system for water detection (AUTOWADE), and the hydraulic model TELEMAC-2D, was operated in real-time to predict the Apollo weather evolution as well as its hydrological and hydraulic impacts, in support of the early warning activities of the Italian Civil Protection Department. The WRF model assimilating radar data and in situ weather stations showed very good predictive capability for rainfall timing and location over eastern Sicily, thus supporting accurate river flow peak forecasting with the hydrological model Continuum. Based on WRF predictions, the daily automatic system for water detection (AUTOWADE) run using Sentinel 1 data was anticipated with respect to the scheduled timing to quickly produce a flood monitoring map. Ad hoc tasking of the COSMO-SkyMed satellite constellation was also performed to overcome the S1 data latency in eastern Sicily. The resulting automated operational mapping of floods and inland waters was integrated with the subsequent execution of the hydraulic model TELEMAC-2D to have a complete representation of the flooded area with water depth and water velocity.

Satellite Radar and Camera Time Series Reveal Transition from Aligned to Distributed Crater Arrangement during the 2021 Eruption of Cumbre Vieja, La Palma (Spain)

Magma-filled dikes may feed erupting fissures that lead to alignments of craters developing at the surface, yet the details of activity and migrating eruptions at the crater row are difficult to monitor and are hardly understood. The 2021 Tajogaite eruption at the Cumbre Vieja, La Palma (Spain), lasted 85 days and developed a pronounced alignment of craters that may be related to changes within the volcano edifice. Here, we use COSMO-SkyMed satellite radar data and ground-based time-lapse photographs, offering a high-resolution dataset to explore the locations and characteristics of evolving craters. Our results show that the craters evolve both gradually and suddenly and can be divided into three main phases. Phase 1, lasting the first 6 weeks of the eruption, was characterized by a NW–SE linear evolution of up to seven craters emerging on the growing cone. Following two partial collapses of the cone to the northwest and a seismicity increase at depth, Phase 2 started and caused a propagation of the main activity toward the southeastern side, together with the presence of up to 11 craters along this main NW–SE trend. Associated with strong deep and shallow earthquakes, Phase 3 was initiated and continued for the final 2 weeks of the eruption, expressed by the development of up to 18 craters, which became dominant and clustered in the southeastern sector in early December 2021. In Phase 3, a second and oblique alignment and surface fracture was identified. Our findings that crater and eruption changes coincide together with an increase in seismic activity at depth point to a deep driver leading to crater and morphology changes at the surface. These also suggest that crater distributions might allow for improved monitoring of changes occurring at depth, and vice versa, such that strong seismicity changes at depth may herald the migration and new formation of craters, which have major implications for the assessment of tephra and lava flow hazards on volcanoes.

Synthetic Aperture Radar Doppler Tomography Reveals Details of Undiscovered High-Resolution Internal Structure of the Great Pyramid of Giza

A problem with synthetic aperture radar (SAR) is that due to the poor penetrating action of electromagnetic waves inside solid bodies, the capability to observe inside distributed targets is precluded. Under these conditions, imaging action is provided only on the surface of distributed targets. The present work describes an imaging method based on the analysis of micro-movements on the Khnum-Khufu Pyramid, which are usually generated by background seismic waves. The obtained results prove to be very promising, as high-resolution full 3D tomographic imaging of the pyramid’s interior and subsurface was achieved. Khnum-Khufu becomes transparent when observed in the micro-movement domain. Based on this novelty, we have completely reconstructed internal objects, observing and measuring structures that have never been discovered before. The experimental results are estimated by processing series of SAR images from the second-generation Italian COSMO-SkyMed satellite system, demonstrating the effectiveness of the proposed method.

Multi-Temporal SAR Interferometry for Vertical Displacement Monitoring from Space of Tengiz Oil Reservoir Using SENTINEL-1 and COSMO-SKYMED Satellite Missions

This study focused on the quantitative assessment of the vertical displacement velocities retrieved using Sentinel-1 and Cosmo-SkyMed synthetic aperture radar images for the Tengiz oilfield. Tengiz oilfield was selected as a study area because of its historically reported continuous subsidence and limited up-to-date studies during recent years. The small baseline subset time-series technique was used for the interferometric processing of radar images acquired for the period of 2018–2020. The geospatial and statistical analyses allowed to determine the existing hotspots of the subsidence processes induced by oil extraction in the study area. Ground deformation measurements derived from the Sentinel-1 and COSMO-SkyMed satellite missions showed that the Tengiz oilfield continuously subsided during 2018–2020 with the maximum annual vertical displacement velocity around −77.4 mm/y and −71.5 mm/y, respectively. The vertical displacement velocities derived from the Sentinel-1 and the COSMO-SkyMed images showed a good statistical relationship with R2≥0.73 and RMSE ≤3.68 mm. The cumulative vertical displacement derived from both satellites for the most subsiding location also showed a good statistical relationship with R2 equal to 0.97 and RMSE = ± 4.69. The observed relative differences of measurements by both satellites were acceptable to determine the ongoing vertical surface displacement processes in the study area. These studies demonstrated a practical novelty for the petroleum industry in terms of the comparative assessment of surface displacement measurements using time-series of medium-resolution Sentinel-1 and high-resolution COSMO-SkyMed radar images.

Investigation of temporal baseline effect on DEMs derived from COSMO Sky-Med data

Digital elevation models (DEM) are indispensable elements of sensitive earth science studies. It is important the production and usage of DEMs. The science of remote sensing offers scientists an important source of data on this subject. Radar data, which is an active remote sensing system, has an important capacity in this regard. DEM production using InSAR data has been widely used in the literature in the last decade. The temporal baseline parameter, which is an important factor in data generation from InSAR pairs, also affects the final products. In this study, it is aimed to examine the usability of these data by producing short (4days), medium (84 days) and long (440 days) baseline DEMs using InSAR pairs of COSMO Sky-Med satellite. At the same time, photogrammetric DEMs were produced with unmanned aerial vehicles (UAV) in selected pilot areas. The DEMs produced were evaluated in 4 land surface types, namely plain-bare, agricultural, urban and rugged area. In addition, by performing statistical analyzes such as RMSE, MAE, the accuracy of the produced DEMs compared to the DEMs produced with UAV was examined. The results showed that short and medium baseline data give more accurate results than long baseline InSAR pairs. Increasing the temporal baseline, increases the amount of error in the DEMs produced. Also, the effect of land surface types on the produced DEMs was revealed in the results of the study.

Coupling Denoising to Detection for SAR Imagery

Detecting objects in synthetic aperture radar (SAR) imagery has received much attention in recent years since SAR can operate in all-weather and day-and-night conditions. Due to the prosperity and development of convolutional neural networks (CNNs), many previous methodologies have been proposed for SAR object detection. In spite of the advance, existing detection networks still have limitations in boosting detection performance because of inherently noisy characteristics in SAR imagery; hence, separate preprocessing step such as denoising (despeckling) is required before utilizing the SAR images for deep learning. However, inappropriate denoising techniques might cause detailed information loss and even proper denoising methods does not always guarantee performance improvement. In this paper, we therefore propose a novel object detection framework that combines unsupervised denoising network into traditional two-stage detection network and leverages a strategy for fusing region proposals extracted from both raw SAR image and synthetically denoised SAR image. Extensive experiments validate the effectiveness of our framework on our own object detection datasets constructed with remote sensing images from TerraSAR-X and COSMO-SkyMed satellites. Extensive experiments validate the effectiveness of our framework on our own object detection datasets constructed with remote sensing images from TerraSAR-X and COSMO-SkyMed satellites. The proposed framework shows better performances when we compared the model with using only noisy SAR images and only denoised SAR images after despeckling under multiple backbone networks.

Modeling historical subsidence due to groundwater withdrawal in the Alto Guadalentín aquifer-system (Spain)

Abstract The Alto Guadalentin Basin (Spain) is widely recognized as an area of major anthropogenic land subsidence due to groundwater extraction. This paper presents a numerical methodology to quantify the severe subsidence of this basin over history. First, a 3D groundwater model is proposed to reproduce groundwater evolution in the regional Alto Guadalentin aquifer system since 1960, leading to an average piezometric level drop of 150 m. Secondly, a generalized plasticity state parameter-based model is calibrated to reproduce the mechanical behavior, observed in oedometer laboratory tests, of compressible materials extracted from a 300-m drilled borehole located in the area of maximum subsidence. The strength of this constitutive model is that a single set of material parameters can be used to reproduce the mechanical behavior of material located at different depths, hence having different confining pressures and void ratio states. Afterwards, subsidence is assessed through a partially saturated 1D vertical finite element model, solving Biot equations that reproduce the slow vertical drainage and vertical consolidation processes, taking into account the calibrated constitutive model and prescribing the previously computed groundwater evolution of the aquifer. Finally, the subsidence model is adjusted with different displacement data available from 1992: datasets acquired by ERS, ENVISAT, Cosmo-SkyMed satellites and the global positioning system GNSS. The proposed calibrated subsidence model reproduces the 3.1 m subsidence monitored in the period 1992–2018, and quantifies historical subsidence (since 1960) in the Alto Guadalentin Basin area at around 5.8 m. Moreover, the model predicts subsidence of up to 7.3 m by 2100 for an assumed constant hydraulic head from 2012 onward.

MODERN SPACE RADAR SYSTEMS OF EARTH MONITORING

This article explores brief overview of modern radar systems for imaging and monitoring the Earth from space. The operating radar systems are divided into four classes: large spacecraft with global monitoring SAR, medium-sized spacecraft with detailed observation SAR, small spacecraft with detailed observation SAR, and commercial mini-spacecraft with detailed observation SAR. Listed are the main representatives of each class. Such large satellites as: European – Sentinel-1 (A, B); Japanese – ALOS-2; Canadian company MDA – Radarsat-2; Argentine – SAOCOM-1A / 1B; Chinese – Gaofen-3. Representatives of the class of mid-size spacecraft with SAR: German Aerospace Center (DLR) and the leading European space company Airbus DS – TerraSAR-X, TanDEM-X; Spanish PAZ; the Italian constellation of Cosmo-SkyMed satellites of the first and second generation; Japanese group IGS-Radar; Korean – KOMPSAT-5; Russian satellites “Kondor”. The small class includes Israeli mission satellites – TecSAR, RISAT-2 (India), Ofeq-10; Japanese – ASNARO-2, German satellites SAR-Lupe, English – NovaSAR-1. The last class of mini-spacecraft includes American - Capella and Finnish – ICEYE. The article also presents spacecraft for radar imaging, planned for launch, namely: the second generation of Italian satellites COSMO-SkyMed – CSG-2; 8 ICEYE spacecrafts (Finland); an increase in the Capella constellation, X-band radar satellites of the SuperView constellation and radar satellites Zhuhai (China); ALOS-4 JAXA (Japan); KOMPSAT-6 (Korea), radar satellites of the IRS constellation (India), American satellites XpressSAR, PredaSAR, EOS SAR, satellites of the Russian design Obzor-R1 and KondorFKA, as well as the space complex planned by ROSKOSMOS, including an orbital constellation of 6 small spacecraft for radar surveillance.

Displacement Monitoring in Airport Runways by Persistent Scatterers SAR Interferometry

Deformations monitoring in airport runways and the surrounding areas is crucial, especially in cases 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 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.

Inferring the Creep Settlement Behavior of Rockfill in Reclaimed Lands by Advanced SAR Interferometry and Numerical Modeling: An Example from Arabian Gulf

Satellite Advanced Differential Synthetic Aperture Radar Interferometry (A-DInSAR) is becaming a key-technique for monitoring ground deformations. The potential of A-DInSAR for settlement monitoring is exploited in this paper through the investigation of a reclaimed land in Dubai (UAE). Time histories of displacements were obtained from COSMO-SkyMed satellite images over the period between 2011 to 2016, allowing to derive the long-term deformation of the entire artificial island. Special attention was paid on long-term settlement of the hydraulically-placed rockfill of the peripheral rubble-mound revetments. The A-DInSAR results have been compared with results derived from numerical analyses and with field surveys, proving the relation between observed and modeled displacements. The study has also revealed that rockfill long-term settlement (creep) rate is significantly dependent on the aging (time since placement). In the analyzed time-frame (2011–2016) it has been observed that recently placed rockfill experienced creep rate up to ten times higher than the creep rate measured for similar rockfill structures placed 30 years earlier. Furthermore, it has been demonstrated that static compression by preloading and dynamic or impact densification induced by wave forces proved to have also a significant impact on reducing the creep rate of the rockfill.

КОСМИЧЕСКИЕ РАДИОЛОКАЦИОННЫЕ СИСТЕМЫ МОНИТОРИНГА ЗЕМЛИ

This article explores the relevance of radar sensing methods. The principles of its operation and the advantages of use are considered: the independence of obtaining images from weather conditions and the time of day, the possibility of wide viewing at long ranges with high resolution and the flexibility of controlling and changing radar parameters, which allows you to vary the position and size of the viewing area, resolution and forms of information. In addition, the main satellite radar systems were considered: satellites of the European Space Agency ERS-1,2 and ENVISAT; Canadian satellites of MDA Radarsat-1,2; satellites launched by the German Aerospace Center (DLR) and the leading European space company Airbus DS-TerraSAR-X, TanDEM-X; Spanish satellite PAZ; Japanese satellites ALOS and ALOS-2; Italian constellation of Cosmo-SkyMed satellites; Indian satellite RISAT-1; English satellite NovaSAR-1; Finnish ICEYE satellites; Korean satellite KOMPSAT-5, Chinese satellite Huan Jing 1C, European satellites Sentinel-1 (A, B) and Russian satellites Condor. Also in this article are considered radar spacecraft planned to launch, namely: the second generation of Italian satellites COSMO-SkyMed – CSG – 2; 2 spacecraft ICEYE (Finland); 4 X-band radar satellites SuperView (China); 2 radar satellites Zhuhai (China); ALOS-4 JAXA (Japan); KOMPSAT-6 (Korea), 3 radar spacecraft of the IRS constellation (India), SAOCOM (Argentina), Russian-made satellites Obzor-P1 and Kondor-FKA, in addition, ROSKOSMOS plans to create a space complex that includes an orbital constellation of 6 small-sized spacecraft for radar observation

A multi-disciplinary approach for the damage analysis of cultural heritage: The case study of the St. Gerlando Cathedral in Agrigento

Protocols for structural safety assessment methods for Cultural Heritage assets affected by ground instability phenomena have still not been standardized. Accordingly, huge attention is directed towards the development of innovative and reliable approaches for the damage analysis of the Cultural Heritage assets. Within this framework, this paper deals with an integrated approach for the combination of deformation time series, derived from the Tomographic processing of X-Band Synthetic Aperture Radar (SAR) data acquired by the Italian COSMO-SkyMed satellite constellation, with ground-based measurements obtained by in-situ survey, laser scanner acquisition and structural analysis. The approach exploits satellite deformation measurements to validate the first interpretation of the structural behaviour of a construction threatened by ground instability based on visual inspection and the analysis of the crack pattern, when geotechnical studies and interpretation, as well as in-situ monitoring systems, are not available.The methodology has been tested on the St. Gerlando Cathedral, located on the westernmost and highest area of the Agrigento hill. The Cathedral is affected by complex ground instability phenomena, that have led to several and continuous cracks over centuries. The spatially dense Tomographic SAR measurements allows accessing differential displacement trends in the different sections of the Cathedral and thereby analyzing the overall kinematic behavior of such a complex and heterogeneous structure. This provides essential information for the definition of the structural models, which are fundamental to better understand the behavior and damage evolution of structures subject to ground instabilities and consequently address the most suitable restoration actions.

SAR Pancake Ice Thickness Retrieval in the Terra Nova Bay (Antarctica) during the PIPERS Expedition in Winter 2017

Pancake and frazil ice represent an important component of the Arctic and Antarctic cryosphere, especially in marginal ice zones. The retrieval of their thickness by remote sensing is, in general, a difficult task. A processing system was developed and refined by the present authors in the framework of the EU SPICES project; it is meant for routinely deriving ice thickness in frazil-pancake regions using the spectral changes in wave spectra from imagery provided by space-borne Synthetic Aperture Radar (SAR) systems. This methodology was successfully tested in the Beaufort Sea through comparison with ground truth collected during the cruise of the “Sikuliaq” in the fall of 2015. In the present study, this technique has been adapted and applied to Antarctic frazil/pancake icefields using COSMO-SkyMed satellite images. Our retrievals were analyzed and validated through a comparison with co-located in situ observations collected during the 2017 PIPERS cruise in Terra Nova Bay polynya. A broad agreement was found between measured thicknesses and those retrieved from the SAR analysis. Results and statistics presented and discussed in detail in this study represent a step towards the autonomous measurement of pancake icefields in remote areas such as Antarctic coastal polynyas and marginal ice zones.

Micro-Motion Estimation of Maritime Targets Using Pixel Tracking in Cosmo-Skymed Synthetic Aperture Radar Data—An Operative Assessment

In this paper, we propose a novel strategy to estimate the micro-motion (m-m) of ships from synthetic aperture radar (SAR) images. To this end, observe that the problem of motion and m-m detection of targets is usually solved using synthetic aperture radar (SAR) along-track interferometry through two radars spatially separated by a baseline along the azimuth direction. The approach proposed in this paper for m-m estimation of ships, occupying thousands of pixels, processes the information generated during the coregistration of several re-synthesized time-domain and not overlapped Doppler sub-apertures. Specifically, the SAR products are generated by splitting the raw data according to a temporally small baseline using one single wide-band staring spotlight (ST) SAR image. The predominant vibrational modes of different ships are then estimated. The performance analysis is conducted on one ST SAR image recorded by COSMO-SkyMed satellite system. Finally, the newly proposed approach paves the way for application to the surveillance of land-based industry activities.

Assessment of capacity of using sentinel-1 images in monitoring land subsidence in Ho Chi Minh City

Permanent Scatterer InSAR (PSInSAR) technique is used commonly to evaluate land subsidence for some cities in the world and the pilot project in Ho Chi Minh City has shown the capability of this technique for mapping land subsidence in the period from 2006 to 2010. The result shows that PSInSAR can be applied to study the land subsidence phenomenon more efficiently than any traditional methods. However, SAR data often are commercial images such as ERS, ALOS, COSMO SkyMed… that a large number of SAR scenes must be collected to ensure the best results. This paper introduces results of the average subsidence velocities in Ho Chi Minh City that PSInSAR technique is applied to process SAR data from Sentinel-1 and COSMO SkyMed satellite. Evaluating the preliminary result showed that the capacity of using free Sentinel-1 images to replace commercial images for monitoring land subsidence.

Anthropogenic subsidence along railway and road infrastructures in Northern Italy highlighted by Cosmo-SkyMed satellite data

We use X-band Cosmo-SkyMed InSAR data to highlight several subsidence phenomena resting on some railway and road infrastructures in Lombardia region, Northern Italy, mainly induced by anthropogenic activities. We show eight case studies, namely “Como,” Erba, Oggiono, Valmadrera, Olginate, Verduggio, Melzo, and San Giuliano M., where we detect local subsidence effects affecting several railway and highway lines with deformation rates of about 5 mm/year. The geological features of this part of Italy and the large presence of industrial areas in the surrounding of Milano, Lecco, and Como cities lead to such phenomena. The stability and security of the nested road and railway network could be affected by these surface deformation fields. To guarantee the safety of people, continuous maintenance of the condition of railways and roads together with the monitoring of the conditions of the lands on which they rest on should be done.