Topological Characterization and Advanced Noise-Filtering Techniques for Phase Unwrapping of Interferometric Data Stacks

This chapter addresses the problem of phase unwrapping interferometric data stacks, obtained by multiple SAR acquisitions over the same area on the ground, with a twofold objective. First, a rigorous gradient-based formulation for the multichannel phase unwrapping (MCh-PhU) problem is systematically established, thus capturing the intrinsic topological character of the problem. The presented mathematical formulation is consistent with the theoretical foundation of the discrete calculus. Then within the considered theoretical framework, we formally describe an innovative procedure for the noise filtering of time-redundant multichannel multilook interferograms. The strategy underlying the adopted multichannel noise filtering (MCh-NF) procedure arises from the key observation that multilook interferograms are not fully time consistent due to multilook operations independently applied on each single interferogram. Accordingly, the presented MCh-NF procedure suitably exploits the temporal mutual relationships of the interferograms. Finally, we present some experimental results on real data and show the effectiveness of our approach applied within the well-known small baseline subset (SBAS) processing chain, thus finally retrieving the relevant Earth’s surface deformation time series for geospatial phenomena analysis and understanding

Satellite SAR Interferometry for Earth’s Crust Deformation Monitoring and Geological Phenomena Analysis

Synthetic aperture radar interferometry (InSAR) and the related processing techniques provide a unique tool for the quantitative measurement of the Earth’s surface deformation associated with certain geophysical processes (such as volcanic eruptions, landslides and earthquakes), thus making possible long-term monitoring of surface deformation and analysis of relevant geodynamic phenomena. This chapter provides an application-oriented perspective on the spaceborne InSAR technology with emphasis on subsequent geophysical investigations. First, the fundamentals of radar interferometry and differential interferometry, as well as error sources, are briefly introduced. Emphasis is then placed on the realistic simulation of the underlying geophysics processes, thus offering an unfolded perspective on both analytical and numerical approaches for modeling deformation sources. Finally, various experimental investigations conducted by acquiring SAR multitemporal observations on areas subject to deformation processes of particular geological interest are presented and discussed

Modelling scattering of electromagnetic waves in layered media: An up-to-date perspective

This paper addresses the subject of electromagnetic wave scattering in layered media, thus covering the recent progress achieved with different approaches. Existing theories and models are analyzed, classified, and summarized on the basis of their characteristics. Emphasis is placed on both theoretical and practical application. Finally, patterns and trends in the current literature are identified and critically discussed

Electromagnetic Wave Sensing in Complex Scenarios: Scattering Models and Applications

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Influence of polyphenols from olive mill wastewater on the gastrointestinal tract, alveolar macrophages and blood leukocytes of pigs

In the last years, great importance has been given to the beneficial effects of polyphenols. Among the most relevant health promoting effects, there is the capacity to reduce the amount of free radicals and stimulate the immune response. In this study, polyphenols extracted from olive mill wastewater (OMWW), were fed to adult 'Casertana' pigs during the finishing period. No significant differences in the length of the jejunum-ileum villi and the depth of the colon crypts were detected between control and polyphenols fed pigs. Instead, intra-epithelial and lamina propria leukocytes were more abundant in pigs fed polyphenols (p < .05). Cyclooxygenase-2 immunoreactivity in the gastrointestinal tract, employed as marker of inflammation, was more intense in the control group. Superoxide anion production in primary cell cultures of both blood leukocytes and alveolar macrophages was lower in pigs fed polyphenols (p < .05). Taken together these data indicate that, according to our in vitro studies, OMWW polyphenols seem to be potent antioxidants, while the interpretation of the in vivo experiments is more problematic and further studies are necessary on the interactions between bioactive feed compounds and intestinal status. Such studies can contribute to a better understanding of both positive and negative interactions in vivo and to the identification of new functional feeds.HIGHLIGHTS The effects of polyphenols extracted from olive mill wastewater (OMWW) have been studied in pigs. Gut morphology, inflammation and immune response were investigated. OMWW polyphenols act as potent antioxidants

Modelling human choices: MADeM and decision‑making

Research supported by FAPESP 2015/50122-0 and DFG-GRTK 1740/2. RP and AR are also part of the Research, Innovation and Dissemination Center for Neuromathematics FAPESP grant (2013/07699-0). RP is supported by a FAPESP scholarship (2013/25667-8). ACR is partially supported by a CNPq fellowship (grant 306251/2014-0)

PERTURBATION THEORY FOR ELECTROMAGNETIC WAVE SCATTERING IN RANDOM LAYERED STRUCTURES

The problem of electromagnetic wave scattering in 3-D random layered structures, is analytical treated by relying on original results of the Boundary Perturbation Theory (BPT) and Volumetric-Perturbative Reciprocal Theory (VPRT), whose structured presentation of the pertinent theoretical body of innovative results is proposed and developed in this thesis. The systematic formulation of Boundary Perturbation Theory (BPT) is here introduced to deal with the analysis of a layered structure with an arbitrary number of gently rough interfaces: in this case the proposed theoretical construct is based on a suitable perturbation pertinent to the geometry of the problem and the scattering problem is treated by adopting a proper perturbation of boundary conditions. Specifically, it is demonstrated that, in the first-order approximation, BPT leads to fully polarimetric, formally symmetric and physical revealing closed form solution: the relevant innovative scattering models obtained in this perturbation framework permit to deal with bistatic scattering, from and through three-dimensional layered structures with an arbitrary number of gently rough interfaces. Furthermore, Volumetric-Perturbative Reciprocal Theory (VPRT) is also formulated in this thesis. VPRT methodologically adopts a different approach, which is based on two key elements: the use of the Reciprocity Theorem and an appropriate description of the scattering structure in terms of space-variant volumetric perturbation of the dielectric constant distribution. The VPRT construct also provides meaningful reaction-based expressions for the scattering field, which are straightforward and rich in descriptive power. It is important to emphasize that VPRT, which is methodologically conceived to consistently treat both interfacial and volumetric random inhomogeneities (so providing a unified mathematical formulation and conceptual understanding of two inherent scattering mechanisms), is also fully consistent with the results of BPT. Accordingly, within VPRT framework, both rough-interface and volume scattering are take into account methodologically. Furthermore, within this new theoretical framework, a new look at the classical SPM solution for rough surface is also offered: even such a specific solution (whose derivation hitherto obtained via unnecessary, involved and obscure algebraic manipulations) is derived a surprisingly simple way, clarifying all the same the lacking inherent physical meaning. Beyond a certain compactness of the pertinent closed-form solutions, the fundamental scattering interactions can be revealed, gaining a coherent explanation and a neat picture of the physical meaning of the proposed theoretical constructs. In fact, it is important to note that a deep comprehension of the physical phenomena involved in the electromagnetic wave scattering interaction with such kind of complex structures would have been a rather hopeless task before the introduction of these theories. Finally, it is noteworthy that this theoretical body of results enables a new way to systematically construct meaningful and general expressions for the scattering field pertinent to wide class of scattering configurations, involving complex structures that can be arranged in a perturbation framework, and it is successful in that it exhibit: conceptual clearness, descriptive power and general applicability to random layered structures

SAR Imaging Distortions Induced by Topography: A Compact Analytical Formulation for Radiometric Calibration

Modeling of synthetic aperture radar (SAR) imaging distortions induced by topography is addressed and a novel radiometric calibration method is proposed in this paper. An analytical formulation of the problem is primarily provided in purely geometrical terms, by adopting the theoretical notions of the differential geometry of surfaces. The novel and conceptually simple formulation relies on a cylindrical coordinate system, whose longitudinal axis corresponds to the sensor flight direction. A 3D representation of the terrain shape is then incorporated into the SAR imaging model by resorting to a suitable parametrization of the observed ground surface. Within this analytical framework, the area-stretching function quantitatively expresses in geometrical terms the inherent local radiometric distortions. This paper establishes its analytical expression in terms of the magnitude of the gradient of the look-angle function uniquely defined in the image domain, thus resulting in being mathematically concise and amenable to a straightforward implementation. The practical relevance of the formulation is also illustrated from a computational perspective, by elucidating its effective discrete implementation. In particular, an inverse cylindrical mapping approach is adopted, thus avoiding the drawback of pixel area fragmentation and integration required in forward-mapping-based approaches. The effectiveness of the proposed SAR radiometric calibration method is experimentally demonstrated by using COSMO-SkyMed SAR data acquired over a mountainous area in Italy