Antonio Natale

Hepatitis E virus genotype 4 in a pig farm, Italy, 2013

Zoonotic strains of hepatitis E virus (HEV) in Europe have been reported to belong to genotypes 3 and 4. In 2012 and 2013, 57 pig farms in Northern Italy that had previously resulted seropositive for HEV were surveyed for the presence of the virus, with positive samples subsequently genotyped. Hepatitis E RNA was identified in 17/57 (29·8%) seropositive farms. Phylogenetic analysis demonstrated that distinct subtypes of genotype 3 were circulating in the north-east of Italy; as well, for the first time in the Italian swine population, genotype 4 was identified and attributed to subtype d.

An X-Band Radar System for Bathymetry and Wave Field Analysis in a Harbour Area

Marine X-band radar based systems are well tested to provide information about sea state and bathymetry. It is also well known that complex geometries and non-uniform bathymetries provide a much bigger challenge than offshore scenarios. In order to tackle this issue a retrieval method is proposed, based on spatial partitioning of the data and the application of the Normalized Scalar Product (NSP), which is an innovative procedure for the joint estimation of bathymetry and surface currents. The strategy is then applied to radar data acquired around a harbour entrance, and results show that the reconstructed bathymetry compares well with ground truth data obtained by an echo-sounder campaign, thus proving the reliability of the whole procedure. The spectrum thus retrieved is then analysed to show the evidence of reflected waves from the harbour jetties, as confirmed by chain of hydrodynamic models of the sea wave field. The possibility of using a land based radar to reveal sea wave reflection is entirely new and may open up new operational applications of the system.

Remocean System for the Detection of the Reflected Waves from the Costa Concordia Ship Wreck

This paper presents the validation of the Remocean X-band wave radar as a tool for sea state monitoring in coastal zones, by processing the data collected and processed by the radar platform installed at the port of Giglio Island. In particular, the effectiveness of the sea wave height reconstruction has been tested during the storm on November 27, 2012, by focusing on the analysis of the spectral slope and the statistical properties of the ocean waves. A further proof of the effectiveness of the system has been shown by comparing both the estimated sea state parameters and 2-D directional spectrum with the benchmark forecasting models WaveWatchIII (WW3) and Simulating Wave Nearshore (SWAN).

Gamma Gaussian Inverse Wishart Probability Hypothesis Density for Extended Target Tracking Using X-Band Marine Radar Data

X-band marine radar systems represent a flexible and low-cost tool for the tracking of multiple targets in a given region of interest. Although suffering several sources of interference, e.g., the sea clutter, these systems can provide high-resolution measurements, both in space and time. Such features offer the opportunity to get accurate information not only about the target position/motion but also about the targets size. Accordingly, in this paper, we exploit emergent extended target tracking (ETT) methodologies in which the target state, typically position/velocity/acceleration, is augmented with the target length and width. In this paper, we propose an ETT procedure based on the popular probability hypothesis density filter, and in particular, we describe the extended target state through the gamma Gaussian inverse Wishart model. The comparative simplicity of the used models allows us to meet the real-time processing constraint required for the practical surveillance purposes. Real-world data from an experimental and operational campaign, collected during the recovery operations of the Costa Concordia wreckage in October 2013, are used to assess the performance of the proposed target tracking methodology. The full signal processing chain is implemented, and considerations of the experimental results are provided. Important nonideal effects, common to every marine radar, are observed and discussed in relation to the assumptions made for the tracking procedure.

Stochastic Theory of Edge Diffraction

We introduce an original formulation for the electromagnetic field diffraction by a knife edge with random roughness: the formulation, based on the asymptotic physical optics approach, leads to closed form evaluations of the statistics of the diffracted field. The edge roughness is described by a stationary zero-mean Gaussian stochastic process with standard deviation sigma and correlation length L. The physical optics approximation is used to evaluate surface currents; mean and variance of the diffracted field are evaluated by means of asymptotic techniques under the hypotheses lambda/r rarr 0, where lambda is the wavelength and r is the distance from the edge, sigma not large with respect to lambda, and sigma/r Lt 1. The main advantages of the proposed method are its simplicity and the fact that, differently from other approaches, the obtained total field is explicitly written as the sum of incident, reflected and diffracted fields. A very interesting conclusion is that, for moderate edge roughness, the diffracted field propagation can be described in terms of the same ray congruence as in the straight (smooth) edge case, with the only difference that the field associated to each ray is a random variable whose statistics are, in this paper, computed in closed form. The presented approach can be then considered as a first step toward a general stochastic theory of edge diffraction. The proposed theoretical results are amenable of interesting practical applications: for instance, the obtained diffracted field statistics can be used to predict the maximum accuracy that can be expected for ray-tracing algorithms that are based on the straight edge assumption.

COSMO-SkyMed AO projects - Use of high resolution SAR data for water resource management in semi arid regions

In this paper we present the results of a project approved in the frame of the 2007 Cosmo-Skymed AO, devoted to use high resolution data for hydrology applications in semi-arid context. A case study was developed in Burkina Faso, a West Africa country, characterized by the alternation of intense rainy and dry seasons. In this paper we present the rationale of the project along with two of the obtained products concerning the estimation of eroded areas and the surface water recharge.

Application of X-Band Wave Radar for Coastal Dynamic Analysis: Case Test of Bagnara Calabra (South Tyrrhenian Sea, Italy)

Sea state knowledge has a key role in evaluation of coastal erosion, the assessment of vulnerability and potential in coastal zone utilization, and development of numerical models to predict its evolution. X-band radar measurements were conducted to observe the spatial and temporal variation of the sea-state parameters along a 3 km long sandy-gravelly pocket beaches forming a littoral cell on Bagnara Calabra. We produced a sequence of 1000 images of the sea state extending offshore up to 1 mile. The survey has allowed monitoring the coastline, the directional wave spectra, the sea surface current fields, and the significant wave heights and detecting strong rip currents which cause scours around the open inlets and affect the stability of the submerged reef-type breakwaters. The possibility to validate the data acquired with other datasets (e.g., LaMMA Consortium) demonstrates the potential of the X-band radar technology as a monitoring tool to advance the understanding of the linkages between sea conditions, nearshore sediment dynamics, and coastal change. This work proves the possibility to obtain relevant information (e.g., wave number, period, and direction) for evaluation of local erosion phenomena and of morphological changes in the nearshore and surf zone.

Radiometric Imaging for Monitoring and Surveillance Issues

This paper deals with the recent advances performed by State Research Center “Iceberg” (SRC) in the field of the passive imaging at millimeter wavelengths. In particular, first the paper describes the design and the realization of two systems working in 3 mm and 8 mm wave bands, respectively. Second, the measurements collected by the two systems are enhanced by means of simple data processing strategies developed by the Institute for Electromagnetic Sensing of the Environment (IREA-CNR).

Estimating Nearshore Bathymetry from X-Band Radar Data

In the last few years, a number of land- and ship-based X-band radar systems have been developed to collect information on the sea state, i.e., on the significant wave height as well as on its spectral distribution. More recently, new techniques have been developed to estimate shallow water bathymetry, by taking into account the effects of depth on the dispersion of gravity waves. This chapter is aimed at reviewing such state-of-the-art algorithms and at providing some examples of applications of the most recent technique. It is shown that the accuracy is fairly adequate for shallow water, but it decreases significantly as the depth increases; besides, because the effects of stationary or nearly stationary currents interfere with the analysis, it is necessary to make use of algorithms that can estimate both depth and currents simultaneously.

Canopy classification with S-band polarimetric SAR data

New Synthetic Aperture Radar (SAR) missions in S-band are currently under design but the potential performance of this microwave frequency is still under discussion. This paper presents the outcomes of a study on canopy classification carried out with fully polarimetric S- and X-band datasets contemporaneously acquired by the Astrium airborne SAR demonstrator. Classical polarimetric decompositions have been applied to investigate the S-band capabilities in vegetation monitoring and preliminary results are here presented.