scholarly journals Imaging Multi-Age Construction Settlement Behaviour by Advanced SAR Interferometry

2018 ◽  
Vol 10 (7) ◽  
pp. 1137 ◽  
Author(s):  
Francesca Bozzano ◽  
Carlo Esposito ◽  
Paolo Mazzanti ◽  
Mauro Patti ◽  
Stefano Scancella
Keyword(s):  
Time Series ◽  
High Resolution ◽  
Boundary Conditions ◽  
Methodological Approach ◽  
Sar Interferometry ◽  
Evolutionary Stage ◽  
Remotely Sensed Data ◽  
Consolidation Process ◽  
Persistent Scatterers ◽  
External Loads

This paper focuses on the application of Advanced Satellite Synthetic Aperture Radar Interferometry (A-DInSAR) to subsidence-related issues, with particular reference to ground settlements due to external loads. Beyond the stratigraphic setting and the geotechnical properties of the subsoil, other relevant boundary conditions strongly influence the reliability of remotely sensed data for quantitative analyses and risk mitigation purposes. Because most of the Persistent Scatterer Interferometry (PSI) measurement points (Persistent Scatterers, PSs) lie on structures and infrastructures, the foundation type and the age of a construction are key factors for a proper interpretation of the time series of ground displacements. To exemplify a methodological approach to evaluate these issues, this paper refers to an analysis carried out in the coastal/deltaic plain west of Rome (Rome and Fiumicino municipalities) affected by subsidence and related damages to structures. This region is characterized by a complex geological setting (alternation of recent deposits with low and high compressibilities) and has been subjected to different urbanisation phases starting in the late 1800s, with a strong acceleration in the last few decades. The results of A-DInSAR analyses conducted from 1992 to 2015 have been interpreted in light of high-resolution geological/geotechnical models, the age of the construction, and the types of foundations of the buildings on which the PSs are located. Collection, interpretation, and processing of geo-thematic data were fundamental to obtain high-resolution models; change detection analyses of the land cover allowed us to classify structures/infrastructures in terms of the construction period. Additional information was collected to define the types of foundations, i.e., shallow versus deep foundations. As a result, we found that only by filtering and partitioning the A-DInSAR datasets on the basis of the above-mentioned boundary conditions can the related time series be considered a proxy of the consolidation process governing the subsidence related to external loads as confirmed by a comparison with results from a physically based back analysis based on Terzaghi’s theory. Therefore, if properly managed, the A-DInSAR data represents a powerful tool for capturing the evolutionary stage of the process for a single building and has potential for forecasting the behaviour of the terrain–foundation–structure combination.

scholarly journals Evaluation of Time Series TanDEM-X Digital Elevation Models

2014 ◽  
Vol XL-8 ◽  
pp. 437-441 ◽  
Author(s):  
M. Jain ◽  
R. Deo ◽  
V. Kumar ◽  
Y. S. Rao
Keyword(s):  
Time Series ◽  
High Resolution ◽  
Time Series Data ◽  
Incidence Angle ◽  
Weighted Average ◽  
Sar Interferometry ◽  
Series Data ◽  
Generation Process ◽  
Digital Elevation ◽  
Elevation Data

Digital Elevation Model (DEM) is an important input for geo-spatial analysis. For various applications like flood management, ortho rectification of remote sensing images, navigation, architectural works, defence, etc., high resolution DEM is required. TanDEM-X mission was launched in 2010 to obtain high resolution global DEM with HTRI-3 standard. SAR interferometry (InSAR) technique is used for DEM generation from TanDEM-X SAR data. The accuracy of DEM depends on many parameters like height ambiguity, incidence angle, polarization, etc. In this study, time series TanDEM-X data spanning over 3 years, had processed for generating DEM at the spatial resolution of 6 m and their accuracy had studied using DGPS elevation data and SRTM 90 m DEM. The products generated during DEM generation process are DEM, precision (or height error), coherence, layover and shadow images. Using weighted average fusion technique, ascending and descending DEMs are fused for improving the quality of DEM and to reduce invalid pixels corresponding to layover and shadow areas. Results from time series data were analysed and found RMSE error of fused DEMs is in the range of 2 m to 4 m, while individual DEM has accuracy of 3 m to 6 m with respect to DGPS elevation data. Fused DEMs are having high accuracy as well as less voids. The reduction of voids by fusion, ranges from 40 to 85 % in different combinations of data.

scholarly journals Displacement Monitoring in Airport Runways by Persistent Scatterers SAR Interferometry

2020 ◽  
Vol 12 (21) ◽  
pp. 3564 ◽  
Author(s):  
Luca Bianchini Ciampoli ◽  
Valerio Gagliardi ◽  
Chiara Ferrante ◽  
Alessandro Calvi ◽  
Fabrizio D’Amico ◽  
...  
Keyword(s):  
Time Series ◽  
Leonardo Da Vinci ◽  
Sar Interferometry ◽  
Subgrade Soils ◽  
Ground Deformations ◽  
Persistent Scatterers ◽  
Deformation Velocity ◽  
Open Issue ◽  
Remote Sensing Techniques ◽  
Surrounding Areas

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.

scholarly journals The position of confirmed pre-main sequence pulsators in the H-R diagram and an overview of their properties

2013 ◽  
Vol 9 (S301) ◽  
pp. 149-152
Author(s):  
Konstanze Zwintz ◽  
Mike Casey ◽  
David Guenther
Keyword(s):  
Time Series ◽  
High Resolution ◽  
High Precision ◽  
Parameter Space ◽  
Main Sequence ◽  
Evolutionary Stage ◽  
Main Sequence Stars ◽  
Pms Stars ◽  
Space Data ◽  
Established Group

AbstractPre-main sequence (PMS) stars can become vibrationally unstable during their evolution to the zero-age main sequence (ZAMS). As they gain their energy from gravitational contraction and have not started nuclear fusion in their cores yet, their inner structures are significantly different to those of (post-) main sequence stars and can be probed by asteroseismology.Using photometric time series from ground and from space (MOST, CoRoT & Spitzer) the number of confirmed pulsating pre-main sequence stars has increased significantly within the last years and allowed to find members of new classes of PMS pulsators. Apart from the well-established group of δ Scuti type PMS stars, members of the groups of PMS γ Doradus, PMS δ Scuti – γ Doradus hybrid and PMS slowly pulsating B (SPB) stars have been discovered. For five PMS δ Scuti candidates, space photometry has revealed that they only show irregular variability, but no pulsations.The unique high-precision space data were combined with dedicated high-resolution spectra to probe the parameter space in the H-R diagram and study the properties of PMS pulsators in comparison to their evolutionary stage.

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