Psi clustering for the assessment of underground infrastructure deterioration

Remote sensing images find application in several different domains, such as land cover or land usage observation, environmental monitoring, and urbanization. This latter field has recently witnessed an interesting development with the use of remote sensing for infrastructural monitoring. In this work, we present an analysis of Sentinel-1 images, which were used to monitor the Italian provinces of Bologna and Modena located at the Emilia Region Apennines foothill. The goal of this study was the development of a machine learning-based detection system to monitor the deterioration of public aqueduct infrastructures based on Persistent Scatterer Interferometry (PSI). We evaluated the land deformation over a temporal range of five years; these series feed a k-means clustering algorithm to separate the pixels of the region according to different deformation patterns. Furthermore, we defined the critical areas as those areas where different patterns collided or overlapped. The proposed approach provides an informative tool for the structural health monitoring of underground infrastructures

The hArtes Tool Chain

This chapter describes the different design steps needed to go from legacy code to a transformed application that can be efficiently mapped on the hArtes platform

Discrimination of different sources of signals in Permanent Scatterers technique by means of Independent Component Analysis

The analysis of multi-temporal SAR data-sets encountered large interest in the remote sensing community during the past few years. The main effort goes toward the extraction of ground displacements signals by means of differential interferometric techniques. In this operational framework an important processing step concerns the estimation and subtraction of signals due to atmospheric artifacts and processing errors. In the present work we apply the technique of Blind Source Separation (BSS) by using the algorithm of Independent Component Analysis (ICA) to Permanent Scatterer processing in order to perform the separation of different signal components. Preliminary investigations are carried out both on simulated and real ERS-1/2 data and results are reported and commented

Using COSMO/SkyMed X-band and ENVISAT C-band SAR interferometry for landslides analysis

Abstract: We explore new possibilities offered by the recently available X-band satellite radar sensors for landslide hazard assessments on a detailed scale, with particular reference to the exploitation of Persistent Scatterers Interferometry (PSI) techniques. Special attention is paid to the impact of the improved resolution of new X-band radar imagery on the PSI results, in terms of quality and quantity of useful information. This evaluation is supported by theoretical modelling as well as by the comparison of results from x-band (CSK) and C-band (ENVISAT) PSI for two areas of interest: one in Italy and the other in Switzerland. It is demonstrated that with respect to medium resolution ENVISAT PS processing, fewer CSK high resolution images are sufficient to achieve comparable precision of the mean displacement velocity estimates. This, together with the shorter revisit times provided by the CSK( constellation, can be very important when dealing with emergency situations. Furthermore, it is quantified that from about 3 to 11 times greater PS densities are obtained with the higher resolution X-band data. This implies more information about ground surface displacements as well as improved landslide monitoring and slope instability investigation capabilities. Furthermore, ground displacement measurements can be interpreted without local knowledge of the focus area or in situ controls, and, nonetheless, guide single hillslope instability assessments with support of Google Earth and its high resolution optical imagery. This "blind" approach will allow one to monitor remote and poorly known regions at high risk of potentially disastrous slope failures. (C) 2011 Elsevier Inc. All rights reserved

APPLICATIONS OF MEDIUM C-BAND AND HIGH RESOLUTION X-BAND MULTITEMPORAL INTERFEROMETRY IN LANDSLIDE INVESTIGATIONS

With the increasing quantity and quality of the imagery available from a growing number of SAR satellites and the improved processing algorithms, multi-temporal interferometry (MTI) is expected to be commonly applied in landslide studies. MTI can now provide long-term (years), regular (weekly-monthly), precise (mm) measurements of ground displacements over large areas (thousands of km2), at medium (~20 m) to high (up to 1-3 m) spatial resolutions, combined with the possibility of multi-scale (regional to local) investigations, using the same series of radar images. We focus on the benefits as well as challenges of multisensor and multi-scale investigations by discussing MTI results regarding two landslide prone regions with distinctly different topographic, climatic and vegetation conditions (mountains in Central Albania and Southern Gansu, China), for which C-band (ERS or ENVISAT) and X-band COSMO-SkyMed (CSK) imagery was available (all in Stripmap descending mode). In both cases X-band MTI outperformed C-band MTI by providing more valuable information for the regional to local scale detection of slope deformations and landslide hazard assessment. This is related to the better spatial-temporal resolutions and more suitable incidence angles (40°-30° versus 23°) of CSK data While the use of medium resolution imagery may be appropriate and more cost-effective in reconnaissance or regional scale investigations, high resolution data could be preferentially exploited when focusing on urbanized landslides or potentially unstable slopes in urban/peri-urban areas, and slopes traversed by lifelines and other engineering structures

Spatial distribution of subsidence in the Wieliczka Salt Mine area as detected through satellite interferometry

The paper presents the use of the Persistent Scatterers Interferometry (PSI) Synthetic Aperture Radar (SAR) data to determine magnitude of subsidence in area of the town ofWieliczka. The town is home to a unique salt mine, over 700 years old, one of the best known tourist attractions in Poland. Each year the mine is visited by about 1 million tourists from all over the world and in 1978 UNESCO placed it on its first International List of theWorld Cultural and Natural Heritage. There is direct evidence that the mining has been influencing stability of ground and buildings in the town, which is located above the mine. The application of the PSI SPINUA technique made it possible to identify large number of radar targets (with density exceeding 100 PS/km2), suitable for monitoring ground motion in the Wieliczka area. The results show continuous subsidence with average annual movements ranging from a few millimeter per year to 24 mm/yr in the period 1992–2000. The detected subsiding zone very well corresponds to the extent of the underground salt mine. There are also indications of possible connections between the mine-induced subsidence and the presence of the old large landslides occurring on the north-facing slopes south of the Wieliczka Salt Mine

Methodological and Technological Advances in the Application of Spaceborne DInSAR for Landslide Monitoring

Differential Interferometry Synthetic Aperture Radar is a mature remote sensing technique broadly used for the measurement of slow deformations with major application in several fields. In the last years, the application to slow moving landslides has grown quickly and several examples of the monitoring capability can be found in the literature. Main goal of this work is the description of the advances in terms of products that can be achieved from both an innovative methodological approach to DInSAR data analysis and the technological improvements related to the last generation of sensors

Postseismic Deformation Monitoring With the COSMO/SKYMED Constellation

COSMO/SKYMED is currently the unique constellation of synthetic aperture radar (SAR) sensors operative, which is also for civilian use. On April 6, 2009, an Mw 6.3 earthquake struck the city of l'Aquila in Central Italy. The constellation acquired data stacks over the hit area at an unprecedented temporal rate. In this letter, the results obtained by processing several data set via two independent multitemporal differential interferometric SAR techniques are presented to demonstrate the capability of this constellation in postseismic deformations monitoring