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result(s) for
"Morello, Giuseppe"
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Positioning Accuracy Comparison of GNSS Receivers Used for Mapping and Guidance of Agricultural Machines
by
Roma, Eliseo
,
Morello, Giuseppe
,
Catania, Pietro
in
Accuracy
,
Agricultural economics
,
Agriculture
2020
Global Navigation Satellite Systems (GNSS) allow the determination of the 3D position of a point on the Earth’s surface by measuring the distance from the receiver antenna to the orbital position of at least four satellites. Selecting and buying a GNSS receiver, depending on farm needs, is the first step for implementing precision agriculture. The aim of this work is to compare the positioning accuracy of four GNSS receivers, different for technical features and working modes: L1/L2 frequency survey-grade Real-Time Kinematic (RTK)-capable Stonex S7-G (S7); L1 frequency RTK-capable Stonex S5 (S5); L1 frequency Thales MobileMapper Pro (TMMP); low-cost L1 frequency Quanum GPS Logger V2 (QLV2). In order to evaluate the positioning accuracy of these receivers, i.e., the distance of the determined points from a reference trajectory, different tests, distinguished by the use or not of Real-Time Kinematic (RTK) differential correction data and/or an external antenna, were carried out. The results show that all satellite receivers tested carried out with the external antenna had an improvement in positioning accuracy. The Thales MobileMapper Pro satellite receiver showed the worst positioning accuracy. The low-cost Quanum GPS Logger V2 receiver surprisingly showed an average positioning error of only 0.550 m. The positioning accuracy of the above-mentioned receiver was slightly worse than that obtained using Stonex S7-G without the external antenna and differential correction (maximum positioning error 0.749 m). However, this accuracy was even better than that recorded using Stonex S5 without differential correction, both with and without the external antenna (average positioning error of 0.962 m and 1.368 m).
Journal Article
Spatio-temporal patterns of fish acoustic communities in Western Mediterranean coralligenous reefs: optimizing monitoring through recording duration
by
Ceccherelli, Giulia
,
Moro Merella, Mariangela
,
La Manna, Gabriella
in
biodiversity
,
cryptic species
,
fish acoustic community
2024
In this study, we explored the fish acoustic community at two coralligenous sites in Sardinia (Tavolara and Santa Teresa, western Mediterranean Sea) during the summer 2023. Our goal was to understand spatial and temporal patterns of fish acoustic activity on different temporal scales to offer insights for optimizing acoustic monitoring of this crucial ecosystem. We identified seventeen distinct sound types, revealing a diverse acoustic community. Tavolara had higher acoustic richness and abundance compared to Santa Teresa, which may be attributed to site-specific factors such as habitat structure, species composition, or levels of protection. Temporal analysis revealed clear diel patterns, with certain sounds associated with nocturnal or diurnal periods, reflecting the daily rhythms of different species. The study also examined how recording duration influenced acoustic richness, finding that longer recordings (15 minutes per hour and 15 minutes per hour at night) provided a more comprehensive detection of acoustic activity. Additionally, the number of recording days required to detect species richness varied depending on the site. While extended recordings improve the likelihood of detecting rare or sporadic sounds, they also present challenges in data management and equipment maintenance. The study underscores the importance of carefully planning sampling strategies to optimize acoustic monitoring and ensure effective and sustainable ecological research in coralligenous ecosystems.
Journal Article
Effects of the Extraction Technology on Pomegranate Juice Quality
by
Catania, Pietro
,
Comparetti, Antonio
,
De Pasquale, Claudio
in
Anthocyanins
,
antioxidant activity
,
dietary supplements
2020
Pomegranate juice is a rich source of phenolic components; its consumption has considerably increased throughout the world in recent years, due to its nutraceutical properties. Commercial juice production involves pressing the fruits. The aim of this study was to assess the influence of the pressing stage on pomegranate juice properties, in terms of value, duration of the applied pressure and juice yield in order to examine the influence of pressure level on volatiles and nutraceutical properties of the juice. Pomegranate fruits cv. Wonderful One were manually harvested and mechanically processed for extracting the juice by means of a shelling machine, a peristaltic pump and a pneumatic press. Chemical analytical determinations were performed on the juice samples corresponding to the different pressure levels applied. They did not show a univocal trend with respect to the increase in pressure; total phenol content values gradually increased as the pressure applied increased, conversely the highest total anthocyanins value was obtained in the first step of the process (552 mg L−1), afterwards a 40% decrease occurred. More than forty Volatile Organic Compounds were identified in the obtained pomegranate juices. The results showed a significant increase in the values in some compounds, particularly for pressure values higher than 0.7 bar, while in others there was a significant decrease as pressure increases. Therefore, the application of different pressure values during pomegranate juice extraction process allowed to obtain products of different quality.
Journal Article
Song Notes and Patterns of the Mediterranean Fin Whale (Balaenoptera physalus) in the Ionian Sea
by
Embriaco, Davide
,
Morello, Giuseppe
,
Simeone, Francesco
in
20-Hz songs
,
acoustic communication
,
Acoustic data
2023
The Mediterranean fin whale emits two types of 20-Hz calls, known as “classic” and “backbeat”, that can be produced in irregular series or in patterned sequences called songs. The analysis of songs is recognized as a meaningful approach to study baleen whales and can be used to investigate populations’ identities. Mediterranean fin whale songs have been studied previously, but only in the western Mediterranean Sea. This work describes the structure of the songs recorded in the Ionian Sea. The inter-note intervals and the alternation of 20-Hz note types were considered to assess the occurrence of recurring patterns. Differences between patterned songs and irregular sequences were also investigated. Acoustic data were sampled continuously for about 10 months by the cabled observatory NEMO-SN1, deployed at 2100 m depth, 25 km offshore Catania; 28 call sequences were isolated and 10 of these were classified as either patterned songs or irregular sequences. Significant differences were observed in the spectral features of classic notes between songs and irregulars; four-note patterns were found repeatedly over different months, indicating a regular structure in detected songs. This work establishes a reference to interpret Mediterranean fin whale songs, and to assess the acoustic behavior of the population.
Journal Article
Whole body vibrations during field operations in the vineyard
by
Catania, Pietro
,
Febo, Pierluigi
,
Vallone, Mariangela
in
Agricultural equipment
,
Agricultural industry
,
Occupational exposure
2013
Human exposure to mechanical vibration can be a significant risk factor for exposed workers and this also occurs in the agricultural sector, in particular with reference to the driver of the tractor during field operations. The aim of this paper is the evaluation of Whole Body Vibrations for the operator driving tractors during the field operations in the vineyard. The experimental tests were performed using a wheeled and a track-laying tractor.
Journal Article
Identification of carbon dioxide in an exoplanet atmosphere
by
Line, Michael R
,
Piette, Anjali A A
,
Mancini, Luigi
in
Absorption
,
Atmosphere
,
Atmospheric models
2023
Carbon dioxide (CO2) is a key chemical species that is found in a wide range of planetary atmospheres. In the context of exoplanets, CO2 is an indicator of the metal enrichment (that is, elements heavier than helium, also called 'metallicity'), and thus the formation processes of the primary atmospheres of hot gas giants. It is also one of the most promising species to detect in the secondary atmospheres of terrestrial exoplanets. Previous photometric measurements of transiting planets with the Spitzer Space Telescope have given hints of the presence of CO2, but have not yielded definitive detections owing to the lack of unambiguous spectroscopic identification. Here we present the detection of CO2 in the atmosphere of the gas giant exoplanet WASP-39b from transmission spectroscopy observations obtained with JWST as part of the Early Release Science programme. The data used in this study span 3.0-5.5 micrometres in wavelength and show a prominent CO2 absorption feature at 4.3 micrometres (26-sigma significance). The overall spectrum is well matched by one-dimensional, ten-times solar metallicity models that assume radiative-convective-thermochemical equilibrium and have moderate cloud opacity. These models predict that the atmosphere should have water, carbon monoxide and hydrogen sulfide in addition to CO2, but little methane. Furthermore, we also tentatively detect a small absorption feature near 4.0 micrometres that is not reproduced by these models.
Journal Article
Data availability and requirements relevant for the Ariel space mission and other exoplanet atmosphere applications
by
Carrasco, Nathalie
,
Rinaldi, Giovanna
,
Grübel, Fabian
in
Atmosphere
,
Atmospheric chemistry
,
Cross-sections
2024
ABSTRACT The goal of this white paper is to provide a snapshot of the data availability and data needs primarily for the Ariel space mission, but also for related atmospheric studies of exoplanets and cool stars. It covers the following data-related topics: molecular and atomic line lists, line profiles, computed cross-sections and opacities, collision-induced absorption and other continuum data, optical properties of aerosols and surfaces, atmospheric chemistry, UV photodissociation and photoabsorption cross-sections, and standards in the description and format of such data. These data aspects are discussed by addressing the following questions for each topic, based on the experience of the ‘data-provider’ and ‘data-user’ communities: (1) what are the types and sources of currently available data, (2) what work is currently in progress, and (3) what are the current and anticipated data needs. We present a GitHub platform for Ariel-related data, with the goal to provide a go-to place for both data-users and data-providers, for the users to make requests for their data needs and for the data-providers to link to their available data. Our aim throughout the paper is to provide practical information on existing sources of data whether in data bases, theoretical, or literature sources.
Journal Article
A machine-learning approach to exoplanet spectroscopy: high-precision data analysis of spectrophometric observations of exoplanetary transits and eclipses
2016
The characterization of exoplanetary atmospheres is the new frontier in the field of exoplanets. Transit and eclipse spectroscopy are invaluable sources of information, as they may reveal the chemical composition, the presence of clouds, and the temperature and pressure profiles of the atmospheres of exoplanets. A photometric precision of about one part in 104 is necessary to make statistically significant inferences. The native calibration of current observatories, except Kepler, is not sufficient to reach this precision. In the past, parametric models have been used extensively by most teams to remove instrumental systematics. This approach has caused many debates regarding the use of different parametric choices for the removal of systematic errors. Parametric models decorrelate the systematic noise with the aid of auxiliary information on the instrument: the so-called optical state vectors (OSVs). Such OSVs can include inter- and intra-pixel position of the star or its spectrum, instrument temperatures and inclinations, and/or other parameters. The choice of the parameters to include in the OSVs is somewhat arbitrary, as is the choice of the functional forms to approximate the dependence of systematic noise on those parameters. The solution to many of the issues deriving from the use of OSVs lies in the use of `blind', non-parametric techniques. Such methods do not require a model for the systematics, and for this reason, they can be applied to any instrument with few changes (if any). In this Thesis, I focus on the Independent Component Analysis (ICA) of multiple time series, which performs a linear transformation of those series into maximally independent components. The use of ICA to detrend instrument systematics in exoplanetary light-curves was first proposed by Waldmann (2012). They experimented with spectroscopic light-curves taken with HST/NICMOS and sequential Kepler observations as input light-curves for the ICA. In this Thesis, I present two novel approaches to detrend single photometric observations in a self-consistent way (pixel-ICA), and scanning-mode spectroscopic observations without mixing the signals at different wavelengths (stripe-ICA). The two techniques that I pioneered extend the applicability of ICA to single observations with different instrument design. Some unsupervised preprocessing steps are also tested. The better performances of these algorithms compared to other ones in the literature are demonstrated over a series of Spitzer and Hubble observations, and synthetic data sets. The (re)analysis of archive and new data with similar techniques will cast new light on the characterization of exoplanets.
Dissertation
A SEA BASS on the exoplanet HD209458b
2018
We present here the first application of Stellar and Exoplanetary Atmospheres Bayesian Analysis Simultaneous Spectroscopy (SEA BASS) on real datasets. SEA BASS is a scheme that enables the simultaneous derivation of four-coefficient stellar limb-darkening profiles, transit depths, and orbital parameters from exoplanetary transits at multiple wavelengths. It relies on the wavelength-independence of the system geometry and on the reduced limb-darkening effect in the infrared. This approach has been introduced by Morello et al. (2017) (without the SEA BASS acronym), who discuss several tests on synthetic datasets. Here, we (1) improve on the original algorithm by using multiple Spitzer/InfraRed Array Camera passbands and a more effective set of geometric parameters, (2) demonstrate its ability with Hubble Space Telescope/Space Telescope Imaging Spectrograph datasets, by (3) measuring the HD209458 stellar limb-darkening profile over multiple passbands in the 290-570 nm range with sufficient precision to rule out some theoretical models that have been adopted previously in theliterature, and (4) simultaneously extracting the transmission spectrum of the exoplanet atmosphere. The higher photometric precision of the next-generation instruments, such as those onboard the James Webb Space Telescope, will enable modeling the star-planet systems with unprecedented detail, and increase the importance of SEA BASS for avoiding the potential biases introduced by inaccurate stellar limb-darkening models.
Is binning always sinning? The impact of time-averaging for exoplanet phase curves
by
Dyrek, Achrène
,
Changeat, Quentin
,
Morello, Giuseppe
in
Extrasolar planets
,
Mathematical analysis
,
Parameters
2022
We explore how finite integration time or temporal binning can affect the analysis of exoplanet phase-curves. We provide analytical formulae to account for this effect or, if neglected, to estimate the potential biases in the retrieved parameters. As expected, due to their smoother variations over longer time-scales, phase curves can be binned more heavily than transits without causing severe biases. In the simplest case of a sinusoidal phase curve with period \\(P\\), the integration time \\(\\Delta t\\) reduces its amplitude by the scaling factor \\(\\text{sinc}{ \\left ( \\pi \\Delta t / P \\right ) }\\), without altering its phase or shape. We also provide formulae to predict reasonable parameter error bars from phase-curve observations. Our findings are tested with both synthetic and real datasets, including unmodelled astrophysical signals and/or instrumental systematic effects. Tests with the Spitzer data show that binning can affect the best-fitting parameters beyond predictions, due to the correction of high-frequency correlated noise. Finally, we summarize key guidelines for speeding up the analysis of exoplanet phase curves without introducing significant biases in the retrieved parameters.