Search results for "Radar"
showing 10 items of 248 documents
Exceeding the resolving imaging power using environmental conditions
2007
We present two approaches that use the environmental conditions in order to exceed the classical Abbe's limit of resolution of an aperture-limited imaging system. At first we use water drops in order to improve the resolving capabilities of an imaging system using a time-multiplexing approach. The limit for the resolution improvement capabilities is equal to the size of the rain drops. The rain drops falling close to the imaged object act as a sparse and random high-resolution mask attached to it. By applying proper image processing, the center of each falling drop is located, and the parameters of the encoding grating are extracted from the captured set of images. The decoding is done digi…
Monitoring Mediterranean marine pollution using remote sensing and hydrodynamic modelling
2011
Human activities contaminate both coastal areas and open seas, even though impacts are different in terms of pollutants, ecosystems and recovery time. In particular, Mediterranean offshore pollution is mainly related to maritime transport of oil, accounting for 25% of the global maritime traffic and, during the last 25 years, for nearly 7% of the world oil accidents, thus causing serious biological impacts on both open sea and coastal zone habitats. This paper provides a general review of maritime pollution monitoring using integrated approaches of remote sensing and hydrodynamic modeling; focusing on the main results of the MAPRES (Marine pollution monitoring and detection by aerial survei…
Optimal Design of an X-Band, Fully-Coaxial, Easily-Tunable Broadband Power Equalizer for a Microwave Power Module
2020
A microwave power module (MPM), which is a hybrid combination of a solid-state power amplifier (SSPA) as a driver and a traveling-wave tube amplifier (TWT) as the final high power stage, is a high-power device largely used for radar applications. A gain equalizer is often required to flatten the TWT output power gain owing to its big gain fluctuations over the operating frequency range. In this paper, the design of an X-band, fully-coaxial, easily-tunable broadband power equalizer for an MPM is presented. The structure is composed of a coaxial waveguide as the main transmission line and a coaxial cavity loaded with absorbing material as a resonant unit. Sensitivity analyses of the attenuati…
Detection and Recognition of Target Signals in Radar Clutter via Adaptive CFAR Tests
2006
In this paper, adaptive CFAR tests are described which allow one to classify radar clutter into one of several major categories, including bird, weather, and target classes. These tests do not require the arbitrary selection of priors as in the Bayesian classifier. The decision rule of the recognition techniques is in the form of associating the p-dimensional vector of observations on the object with one of the m specific classes. When there is the possibility that the object does not belong to any of the m classes, then this object is to be classified as belonging to one of the m classes or to class m+1 whose distribution is unspecified. The tests are invariant to intensity changes in the …
Combining single polarization X-band radar and ground devices for hydrological applications
2015
Recently, the Department of Civil, Environmental, Aerospace Engineering, and Materials (DICAM) of the University of Palermo (Italy) has installed several devices for the monitoring of precipitation for the urban area of Palermo. These devices include a single polarization X-band weather radar, a rain gauge network spread over the urban area, and a laboratory site where advanced precipitation devices (an optical disdrometer, a weight rain gauge, and a weather station) are available. Given the ensemble of measurements retrieved by sensors, a set of models for the combination of data has been developed in order to exploit their joint usage. The disdrometer information have been exploited for t…
Exploring single polarization X-band weather radar potentials for local meteorological and hydrological applications
2015
Summary The aim of this study is to evaluate the potential use of a low-cost single polarization X-band weather radar, verified by a disdrometer and a dense rain gauge network, installed as a supporting tool for hydrological applications and for monitoring the urban area of Palermo (Italy). Moreover, this study focuses on studying the temporal variability of the Z–R relation for Mediterranean areas. The radar device is provided with an automatic operational ground-clutter filter developed by the producer. Attention has been paid to the development of blending procedures between radar measurements and other auxiliary instruments and to their suitability for both meteorological and hydrologic…
Improvement of snow physical parameters retrieval using SAR data in the Arctic (Svalbard)
2018
International audience; Arctic snow cover dynamics offer a changing face in terms of temporal duration andwater equivalent, due to recent climate change conditions (Callaghan et al., 2011; Lemke & Jacobi,2012). Indeed, the Arctic is now experiencing some of the most rapid and severe climate change onearth. In this context, innovative and improved methods are helpful to enhance management of thesnow-pack resource for climate research, hydrology and human activities. The characteristics of Arcticsnow are different from “temperate” snow (i.e. the Alps), in terms of thickness, internal structure, thermalconductivity, and metamorphism. Ground observation often indicates wind slab at the snow sur…
Projectual efficacy of the analytical action: radar survey and historical architecture
2014
Il contributo introduce i risultati delle applicazioni della strumentazione radar a impulsi elettromagnetici condotte su monumenti siciliani e dimostra la loro efficacia analitica e progettuale operando nel contesto dei beni architettonici. Le applicazioni presentate perseguono l'obiettivo di localizzare i difetti ed effettuare valutazioni stratigrafiche senza operare in modo distruttivo, riconoscendo la tipologia delle strutture ed i materiali. L'indagine radar è stata spesso effettuata per valutare la profondità delle fratture o l'efficacia delle tecniche di consolidamento. Gli esiti dell'indagine sulla pavimentazione di maiolica sono elaborati con l'impiego di un software in via di speri…
Indagini diagnostiche nella ex Chiesa Madre di Santa Margherita di Belice
2009
Il testo descrive l’applicazione sperimentale di una nuova metodologia analitica diagnostica basata sullo svolgimento sinergico delle indagini diagnostiche non distruttive. La ricerca si pone l'obiettivo di caratterizzare lo stato di conservazione delle superfici nella ex Chiesa Madre di Santa Margherita di Belice attraverso l'elaborazione della diagnosi che risulti specifica per la redazione del progetto di conservazione e la direzione del relativo cantiere d’intervento. L'applicazione scientifica è svolta nell'ambito della sperimentazione della nuova Metodologia T.R.U.E. e del relativo software.
Verifiche Diagnostiche nell'ex Chiesa Madre di Santa Margherita di Belice
2011
La relazione presenta in modo dettagliato gli esiti della seconda campagna di indagini diagnostiche, svolta nella fabbrica architettonica a cantiere di restauro in corso d'opera. L'obiettivo delle valutazioni non distruttive e minimamente invasive è valutare la corretta esecuzione degli interventi attraverso il confronto tra la diagnosi preliminare e quella post-intervento. The report presents in detail the results of the second campaign of diagnostic investigations, carried out in the architectural restoration site. The goal of minimally invasive and non-destructive evaluation is to assess the proper execution of consolidation through the comparison between the preliminary and post-interve…