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Wasowski J.,CNR Research Institute for Geo-hydrological Protection | Bovenga F.,CNR Institute of Intelligent Systems for Automation
Engineering Geology | Year: 2014

Multi Temporal Interferometry (MTI) stands for advanced synthetic aperture radar differential interferometry (DInSAR) techniques, which include Permanent/Persistent Scatterers Interferometry - PSInSAR™/PSI and similar methods, as well as Small Baseline Subset - SBAS and related/hybrid approaches. These techniques are capable to provide wide-area coverage (thousands of km2) and precise (mm-cm resolution), spatially dense information (from hundreds to thousands of measurement points/km2) on ground surface deformations. New MTI application opportunities are emerging thanks to i) greater data availability from radar satellites, and ii) improved capabilities of the new space radar sensors (X-band Cosmo-SkyMed, C-band RADARSAT-2, TerraSAR-X) in terms of resolution (from 3 to 1m) and revisit time (from 11 to 4days for X-band acquisitions). This implies greater quantity and quality information about ground surface displacements and hence improved landslide detection and monitoring capabilities. Even though the applicability of MTI to regional and local-scale investigations of slow landslides has already been demonstrated, the awareness of the MTI utility and its technical limitations among landslide scientists and practitioners is still rather low. By referring to recent works on radar remote sensing, many regional and local scale MTI application examples from the geoscience literature and our own studies, we present an up-to-date overview of current opportunities and challenges in this field. We discuss relevant technical constraints and data interpretation issues that hamper the use of MTI in landslide assessment. Then guidelines on how to mitigate MTI technical limitations and avoid erroneous interpretations of radar-derived slope surface deformations are presented for the benefit of users lacking advanced knowledge in SAR applications. Finally, in view of the upcoming radar satellite launches, future perspectives on MTI applications are outlined and recommendations for applied research priorities are suggested. We foresee that with regular globe-scale coverage, improved temporal resolution (weekly or better) and freely available imagery, new radar satellite background missions such as the European Space Agency's Sentinel-1 will guarantee ever increasing and more efficient use of MTI in landslide investigations. Furthermore, thanks to the improved temporal and spatial resolutions of the new generation radar sensors, significant breakthroughs are expected in detailed slope instability process modeling (e.g. kinematic and geotechnical models), as well as in the understanding of spatial and temporal patterns of landslide movement/activity and their relationships to causative or triggering factors (e.g. precipitation, seismic loading). © 2014 Elsevier B.V. Source


Tarantino E.,Polytechnic of Bari | Figorito B.,CNR Institute of Intelligent Systems for Automation
Remote Sensing | Year: 2012

Plastic covering is used worldwide to protect crops against damaging growing conditions. This agricultural practice raises some controversial issues. While it significantly impacts on local economic vitality, plasticulture also shows several environmental affects. In the Apulia Region (Italy) the wide-spreading of artificial plastic coverings for vineyard protection has showed negative consequences on the hydrogeological balance of soils as well as on the visual quality of rural landscape. In order to monitor and manage this phenomenon, a detailed site mapping has become essential. In this study an efficient object-based classification procedure from Very High Spatial Resolution (VHSR) true color aerial data was developed on eight test areas located in the Ionian area of the Apulia Region in order to support the updating of the existing land use database aimed at plastic covered vineyard monitoring. © 2012 by the authors. Source


Mattia F.,CNR Institute of Intelligent Systems for Automation
Waves in Random and Complex Media | Year: 2011

A recent experimental study by Wegmuller et al. has reported on directional backscattering patterns in the Synthetic Aperture Radar (SAR) response of bare or sparsely vegetated agricultural soils that require a better understanding of scattering from tilled soils. Shin and Kong modeled the latter as quasi-periodic rough surfaces and showed that the total backscatter consists of three terms, one due to the coherent field and the other two arising from the incoherent scattered field. However, all the simulations reported by Shin and Kong are only concerned with one of the terms contributing to the incoherent scattering and could not predict highly directional backscattering patterns. In this context, the objective of this work is: (1) to extend the Shin-Kong model in order to compute in a finite form all the coherent and incoherent terms; (2) to describe the case of quasi-periodic rough surfaces having quasi-parallel row directions. Results indicate that the new model can predict very narrow (i.e. a few tenths of a degree angular aperture) backscatter peaks when the wave incidence plane is quasi-orthogonal to the row tillage direction. More generally, the paper's results point to the importance of anisotropic tillage patterns in modulating the radar backscatter in the entire azimuthal plane. © 2011 Taylor & Francis. Source


Cervellera C.,CNR Institute of Intelligent Systems for Automation
IEEE Transactions on Neural Networks | Year: 2010

In this brief, the use of lattice point sets (LPSs) is investigated in the context of general learning problems (including function estimation and dynamic optimization), in the case where the classic empirical risk minimization (ERM) principle is considered and there is freedom to choose the sampling points of the input space. Here it is proved that convergence of the ERM principle is guaranteed when LPSs are employed as training sets for the learning procedure, yielding up to a superlinear convergence rate under some regularity hypotheses on the involved functions. Preliminary simulation results are also provided. © 2006 IEEE. Source


Pucci M.,CNR Institute of Intelligent Systems for Automation
Electric Power Systems Research | Year: 2012

This paper deals with direct field oriented control of linear induction motor drives. After elaborating the inductor and induced part space-vector equations of the LIM in several reference frames, some induced part flux models taking into consideration the end effects are presented. In particular, the so called "voltage model" based on the inductor equations in the inductor reference frame and the "current model" based on induced part equations in both the inductor and induced part flux linkage reference frames are deduced and compared to the rotational induction machine counterpart. Afterwards, after a proper tuning of such models based on both FEA (finite element analysis) and experimental measurements, some simulation and experimental tests have been performed. Simulations show that the proposed flux models taking into consideration the LIM end effects permit the drive to achieve better dynamic performance. Moreover, some comparative experimental results, adopting both the current and the voltage flux models, have been performed on a suitably devised test set-up. © 2012 Elsevier B.V. All rights reserved. Source

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