L. Spogli - Academia.edu (original) (raw)

Papers by L. Spogli

... Luca Spogli(1), Lucilla Alfonsi(1),Massimo Materassi (2), Andrzej W. Wernik(3) (1)INGV – Isti... more ... Luca Spogli(1), Lucilla Alfonsi(1),Massimo Materassi (2), Andrzej W. Wernik(3) (1)INGV – Istituto Nazionale di Geofisica e Vulcanologia, via di Vigna Murata 605, 00143 Rome, Italy, luca.spogli@ingv.it (2) Istituto dei Sistemi Complessi, Consiglio Nazionale delle Ricerche, Via ...

In recent years, several groups have installed high-frequency sampling receivers in the southern ... more In recent years, several groups have installed high-frequency sampling receivers in the southern middle and high latitude regions, to monitor ionospheric scintillations and the total electron content (TEC) changes. Taking advantage of the archive of continuous and systematic observations of the ionosphere on L-band by means of signals from the Global Positioning System (GPS), we present the first attempt at ionospheric scintillation and TEC mapping from Latin America to Antarctica. The climatology of the area considered is derived through Ground-Based Scintillation Climatology, a method that can identify ionospheric sectors in which scintillations are more likely to occur. This study also introduces the novel ionospheric scintillation 'hot-spot' analysis. This analysis first identifies the crucial areas of the ionosphere in terms of enhanced probability of scintillation occurrence, and then it studies the seasonal variation of the main scintillation and TEC-related parameters. The results produced by this sophisticated analysis give significant indications of the spatial/ temporal recurrences of plasma irregularities, which contributes to the extending of current knowledge of the mechanisms that cause scintillations, and consequently to the development of efficient tools to forecast space-weather-related ionospheric events.

that are managed and operated by the University of Nottingham (UK). By visiting the eSWua website... more that are managed and operated by the University of Nottingham (UK). By visiting the eSWua website, it is possible to access the database that has been implemented to organize and manage the large amount of information acquired. The section of the database designed for the TEC and scintillation data has been designed to address the needs of the space weather community as well as of scientific users. Through the web tools, it is possible to visualize, plot, extract and download the data from each station. This interactive website is supported by a structured database, and it provides a powerful tool for the scientific and technological community in the field of telecommunications and space weather. At present, the data transmission procedure, the database population algorithm, the linear plot and polar plot visualization tools, the statistics page, and the user management system are fully operational.

In the framework of the project BIS -Bipolar Ionospheric Scintillation and Total Electron Content... more In the framework of the project BIS -Bipolar Ionospheric Scintillation and Total Electron Content Monitoring, the ISACCO-DMC0 and ISACCO-DMC1 permanent monitoring stations were installed in 2008. The principal scope of the stations is to measure the ionospheric total electron content (TEC) and to monitor the ionospheric scintillations, using high-sampling-frequency global positioning system (GPS) ionospheric scintillation and TEC monitor (GISTM) receivers. The disturbances that the ionosphere can induce on the electromagnetic signals emitted by the Global Navigation Satellite System constellations are due to the presence of electron density anomalies in the ionosphere, which are particularly frequent at high latitudes, where the upper atmosphere is highly sensitive to perturbations coming from outer space. With the development of present and future low-frequency space-borne microwave missions (e.g., Soil Moisture and Ocean Salinity [SMOS], Aquarius, and Soil Moisture Active Passive missions), there is an increasing need to estimate the effects of the ionosphere on the propagation of electromagnetic waves that affects satellite measurements. As an example, how the TEC data collected at Concordia station are useful for the calibration of the European Space Agency SMOS data within the framework of an experiment promoted by the European Space Agency (known as DOMEX) will be discussed. The present report shows the ability of the GISTM station to monitor ionospheric scintillation and TEC, which indicates that only the use of continuous GPS measurements can provide accurate information on TEC variability, which is necessary for continuous calibration of satellite data.

Annales Geophysicae, 2011

Arrays of GPS Ionospheric Scintillation and TEC Monitors (GISTMs) are used in a comparative scint... more Arrays of GPS Ionospheric Scintillation and TEC Monitors (GISTMs) are used in a comparative scintillation study focusing on quasi-conjugate pairs of GPS receivers in the Arctic and Antarctic. Intense GPS phase scintillation and rapid variations in ionospheric total electron content (TEC) that can result in cycle slips were observed at high latitudes with dual-frequency GPS receivers during the first significant geomagnetic storm of solar cycle 24 on 5-7 April 2010. The impact of a bipolar magnetic cloud of north-south (NS) type embedded in high speed solar wind from a coronal hole caused a geomagnetic storm with maximum 3-hourly Kp = 8and hourly ring current Dst = −73 nT. The interhemispheric comparison of phase scintillation reveals similarities but also asymmetries of the ionospheric response in the northern and southern auroral zones, cusps and polar caps. In the nightside auroral oval and in the cusp/cleft sectors the phase scintillation was observed in both hemispheres at about the same times and was correlated with geomagnetic activity. The scintillation level was very similar in approximately conjugate locations in Published by Copernicus Publications on behalf of the European Geosciences Union. 2288 P. Prikryl et al.: Interhemispheric comparison of GPS phase scintillation at high latitudes (a) Fig. 1a. The CHAIN and European GISTM arrays (red dots) and fields of view of SuperDARN radars in Saskatoon, Rankin Inlet and Hankasalmi. Conjugate locations of four Antarctic GPS receivers (blue dots) and the field of view of the McMurdo SuperDARN radar (dashed line) are superposed. The location and field of view of an all-sky imager in Fort Smith is shown. Corrected geomagnetic (CGM) latitudes 70 • N and 80 • N and DMSP F17 satellite track are superposed.

Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics, 2011

√ s = 7 TeV measured with the ATLAS detector ✩ .ATLAS Collaboration a r t i c l e i n f o a b s t... more √ s = 7 TeV measured with the ATLAS detector ✩ .ATLAS Collaboration a r t i c l e i n f o a b s t r a c t Dijet angular distributions from the first LHC pp collisions at center-of-mass energy √ s = 7 TeV have been measured with the ATLAS detector. The dataset used for this analysis represents an integrated luminosity of 3.1 pb −1 . Dijet χ distributions and centrality ratios have been measured up to dijet masses of 2.8 TeV, and found to be in good agreement with Standard Model predictions. Analysis of the χ distributions excludes quark contact interactions with a compositeness scale Λ below 3.4 TeV, at 95% confidence level, significantly exceeding previous limits. √ s = 7 TeV at the LHC. The data sample represents an integrated luminosity of 3.1 pb −1 , recorded in periods of stable collisions, through August 2010. The two distributions under

2011 XXXth URSI General Assembly and Scientific Symposium, 2011

Ionospheric scintillations can seriously jeopardize the reliability of the GNSS signals and conse... more Ionospheric scintillations can seriously jeopardize the reliability of the GNSS signals and consequently can cause significant error or outage on precise positioning applications. The threat is most acute at low latitudes where ionospheric irregularities are more likely to occur resulting in L-band signal scintillations. This paper describes the effort made to model the ionospheric scintillations over the Latin American region in the frame of the CIGALA project funded by the European GNSS Supervisory Authority within the 7th Framework Programme of the European Commission. Comparisons between the low-latitude model of scintillations and observations are here presented and discussed within the project perspectives.

We analyse GNSS ionospheric scintillation data in the polar areas of both hemispheres to develop ... more We analyse GNSS ionospheric scintillation data in the polar areas of both hemispheres to develop a climatology over a large geomagnetic quiet period. The conditions of the near-Earth environment leading to scintillation scenarios are investigated via scintillation occurrence. Within this scope we realize maps of scintillation occurrence as a function of the magnetic local time (MLT) and of the altitude adjusted corrected geomagnetic coordinates (AACGM). The maps are realized merging observations from a network of four GISTM (GPS Ionospheric Scintillation and TEC Monitor) in the Northern Europe and two GISTM in Antarctica during the year 2008. The results highlight the possibility to investigate the impact of ionospheric irregularities on the phase and amplitude of GNSS signals, evidencing the auroral and cusp/cap contributions. This works aims to contribute to development of nowcasting and forecasting tools for GNSS ionospheric scintillation.

EGU General …, 2010

... ACKNOWLEDGEMENTS The authors would like to thank Andrzej W. Wernik for his kind support and i... more ... ACKNOWLEDGEMENTS The authors would like to thank Andrzej W. Wernik for his kind support and important comments. The authors also thank the Programma Nazionale di Ricerche in Antartide (PNRA), POLRNET-CNR (Consiglio Nazionale delle Ricerche).

2013 Seventh International Conference on Complex, Intelligent, and Software Intensive Systems, 2013

The ionosphere is the single largest contributor to the GNSS (Global Navigation Satellite System)... more The ionosphere is the single largest contributor to the GNSS (Global Navigation Satellite System) error budget and ionospheric scintillation (IS) in particular is one of its most harmful effects. The Ground Based Scintillation Climatology (GBSC) has been recently developed by INGV as a software tool to identify the main areas of the ionosphere in which IS is more likely to occur. Due to the high computational load required, GBSC is currently used only for scientific, offline, studies and not as a real time service. Recently, a collaboration was initiated between ISMB and INGV in order to identify which cloud service model (IaaS, PaaS or SaaS) is most suitable for implementing the GBSC technique within the cloud computing environment. The aims of this joined effort are twofold: i) to optimize the computational resources allocation strategy/plan for the GBSC service, ii) to fine tune the algorithm for dynamic and real time application, towards a service contributing to high precision professional applications for the GNSS-reliant business sectors. Preliminary result of the implementation of GBSC within the cloud environment will be shown.

... Luca Spogli(1), Lucilla Alfonsi(1),Massimo Materassi (2), Andrzej W. Wernik(3) (1)INGV – Isti... more ... Luca Spogli(1), Lucilla Alfonsi(1),Massimo Materassi (2), Andrzej W. Wernik(3) (1)INGV – Istituto Nazionale di Geofisica e Vulcanologia, via di Vigna Murata 605, 00143 Rome, Italy, luca.spogli@ingv.it (2) Istituto dei Sistemi Complessi, Consiglio Nazionale delle Ricerche, Via ...

In recent years, several groups have installed high-frequency sampling receivers in the southern ... more In recent years, several groups have installed high-frequency sampling receivers in the southern middle and high latitude regions, to monitor ionospheric scintillations and the total electron content (TEC) changes. Taking advantage of the archive of continuous and systematic observations of the ionosphere on L-band by means of signals from the Global Positioning System (GPS), we present the first attempt at ionospheric scintillation and TEC mapping from Latin America to Antarctica. The climatology of the area considered is derived through Ground-Based Scintillation Climatology, a method that can identify ionospheric sectors in which scintillations are more likely to occur. This study also introduces the novel ionospheric scintillation 'hot-spot' analysis. This analysis first identifies the crucial areas of the ionosphere in terms of enhanced probability of scintillation occurrence, and then it studies the seasonal variation of the main scintillation and TEC-related parameters. The results produced by this sophisticated analysis give significant indications of the spatial/ temporal recurrences of plasma irregularities, which contributes to the extending of current knowledge of the mechanisms that cause scintillations, and consequently to the development of efficient tools to forecast space-weather-related ionospheric events.

that are managed and operated by the University of Nottingham (UK). By visiting the eSWua website... more that are managed and operated by the University of Nottingham (UK). By visiting the eSWua website, it is possible to access the database that has been implemented to organize and manage the large amount of information acquired. The section of the database designed for the TEC and scintillation data has been designed to address the needs of the space weather community as well as of scientific users. Through the web tools, it is possible to visualize, plot, extract and download the data from each station. This interactive website is supported by a structured database, and it provides a powerful tool for the scientific and technological community in the field of telecommunications and space weather. At present, the data transmission procedure, the database population algorithm, the linear plot and polar plot visualization tools, the statistics page, and the user management system are fully operational.

In the framework of the project BIS -Bipolar Ionospheric Scintillation and Total Electron Content... more In the framework of the project BIS -Bipolar Ionospheric Scintillation and Total Electron Content Monitoring, the ISACCO-DMC0 and ISACCO-DMC1 permanent monitoring stations were installed in 2008. The principal scope of the stations is to measure the ionospheric total electron content (TEC) and to monitor the ionospheric scintillations, using high-sampling-frequency global positioning system (GPS) ionospheric scintillation and TEC monitor (GISTM) receivers. The disturbances that the ionosphere can induce on the electromagnetic signals emitted by the Global Navigation Satellite System constellations are due to the presence of electron density anomalies in the ionosphere, which are particularly frequent at high latitudes, where the upper atmosphere is highly sensitive to perturbations coming from outer space. With the development of present and future low-frequency space-borne microwave missions (e.g., Soil Moisture and Ocean Salinity [SMOS], Aquarius, and Soil Moisture Active Passive missions), there is an increasing need to estimate the effects of the ionosphere on the propagation of electromagnetic waves that affects satellite measurements. As an example, how the TEC data collected at Concordia station are useful for the calibration of the European Space Agency SMOS data within the framework of an experiment promoted by the European Space Agency (known as DOMEX) will be discussed. The present report shows the ability of the GISTM station to monitor ionospheric scintillation and TEC, which indicates that only the use of continuous GPS measurements can provide accurate information on TEC variability, which is necessary for continuous calibration of satellite data.

Annales Geophysicae, 2011

Arrays of GPS Ionospheric Scintillation and TEC Monitors (GISTMs) are used in a comparative scint... more Arrays of GPS Ionospheric Scintillation and TEC Monitors (GISTMs) are used in a comparative scintillation study focusing on quasi-conjugate pairs of GPS receivers in the Arctic and Antarctic. Intense GPS phase scintillation and rapid variations in ionospheric total electron content (TEC) that can result in cycle slips were observed at high latitudes with dual-frequency GPS receivers during the first significant geomagnetic storm of solar cycle 24 on 5-7 April 2010. The impact of a bipolar magnetic cloud of north-south (NS) type embedded in high speed solar wind from a coronal hole caused a geomagnetic storm with maximum 3-hourly Kp = 8and hourly ring current Dst = −73 nT. The interhemispheric comparison of phase scintillation reveals similarities but also asymmetries of the ionospheric response in the northern and southern auroral zones, cusps and polar caps. In the nightside auroral oval and in the cusp/cleft sectors the phase scintillation was observed in both hemispheres at about the same times and was correlated with geomagnetic activity. The scintillation level was very similar in approximately conjugate locations in Published by Copernicus Publications on behalf of the European Geosciences Union. 2288 P. Prikryl et al.: Interhemispheric comparison of GPS phase scintillation at high latitudes (a) Fig. 1a. The CHAIN and European GISTM arrays (red dots) and fields of view of SuperDARN radars in Saskatoon, Rankin Inlet and Hankasalmi. Conjugate locations of four Antarctic GPS receivers (blue dots) and the field of view of the McMurdo SuperDARN radar (dashed line) are superposed. The location and field of view of an all-sky imager in Fort Smith is shown. Corrected geomagnetic (CGM) latitudes 70 • N and 80 • N and DMSP F17 satellite track are superposed.

Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics, 2011

√ s = 7 TeV measured with the ATLAS detector ✩ .ATLAS Collaboration a r t i c l e i n f o a b s t... more √ s = 7 TeV measured with the ATLAS detector ✩ .ATLAS Collaboration a r t i c l e i n f o a b s t r a c t Dijet angular distributions from the first LHC pp collisions at center-of-mass energy √ s = 7 TeV have been measured with the ATLAS detector. The dataset used for this analysis represents an integrated luminosity of 3.1 pb −1 . Dijet χ distributions and centrality ratios have been measured up to dijet masses of 2.8 TeV, and found to be in good agreement with Standard Model predictions. Analysis of the χ distributions excludes quark contact interactions with a compositeness scale Λ below 3.4 TeV, at 95% confidence level, significantly exceeding previous limits. √ s = 7 TeV at the LHC. The data sample represents an integrated luminosity of 3.1 pb −1 , recorded in periods of stable collisions, through August 2010. The two distributions under

2011 XXXth URSI General Assembly and Scientific Symposium, 2011

Ionospheric scintillations can seriously jeopardize the reliability of the GNSS signals and conse... more Ionospheric scintillations can seriously jeopardize the reliability of the GNSS signals and consequently can cause significant error or outage on precise positioning applications. The threat is most acute at low latitudes where ionospheric irregularities are more likely to occur resulting in L-band signal scintillations. This paper describes the effort made to model the ionospheric scintillations over the Latin American region in the frame of the CIGALA project funded by the European GNSS Supervisory Authority within the 7th Framework Programme of the European Commission. Comparisons between the low-latitude model of scintillations and observations are here presented and discussed within the project perspectives.

We analyse GNSS ionospheric scintillation data in the polar areas of both hemispheres to develop ... more We analyse GNSS ionospheric scintillation data in the polar areas of both hemispheres to develop a climatology over a large geomagnetic quiet period. The conditions of the near-Earth environment leading to scintillation scenarios are investigated via scintillation occurrence. Within this scope we realize maps of scintillation occurrence as a function of the magnetic local time (MLT) and of the altitude adjusted corrected geomagnetic coordinates (AACGM). The maps are realized merging observations from a network of four GISTM (GPS Ionospheric Scintillation and TEC Monitor) in the Northern Europe and two GISTM in Antarctica during the year 2008. The results highlight the possibility to investigate the impact of ionospheric irregularities on the phase and amplitude of GNSS signals, evidencing the auroral and cusp/cap contributions. This works aims to contribute to development of nowcasting and forecasting tools for GNSS ionospheric scintillation.

EGU General …, 2010

... ACKNOWLEDGEMENTS The authors would like to thank Andrzej W. Wernik for his kind support and i... more ... ACKNOWLEDGEMENTS The authors would like to thank Andrzej W. Wernik for his kind support and important comments. The authors also thank the Programma Nazionale di Ricerche in Antartide (PNRA), POLRNET-CNR (Consiglio Nazionale delle Ricerche).

2013 Seventh International Conference on Complex, Intelligent, and Software Intensive Systems, 2013

The ionosphere is the single largest contributor to the GNSS (Global Navigation Satellite System)... more The ionosphere is the single largest contributor to the GNSS (Global Navigation Satellite System) error budget and ionospheric scintillation (IS) in particular is one of its most harmful effects. The Ground Based Scintillation Climatology (GBSC) has been recently developed by INGV as a software tool to identify the main areas of the ionosphere in which IS is more likely to occur. Due to the high computational load required, GBSC is currently used only for scientific, offline, studies and not as a real time service. Recently, a collaboration was initiated between ISMB and INGV in order to identify which cloud service model (IaaS, PaaS or SaaS) is most suitable for implementing the GBSC technique within the cloud computing environment. The aims of this joined effort are twofold: i) to optimize the computational resources allocation strategy/plan for the GBSC service, ii) to fine tune the algorithm for dynamic and real time application, towards a service contributing to high precision professional applications for the GNSS-reliant business sectors. Preliminary result of the implementation of GBSC within the cloud environment will be shown.