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Thorossian, William
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Thorossian, William
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william.thorossian@ingv.it
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8 results
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- PublicationOpen AccessFirst results of CISA, the new Central Italy Seismic Array(2019-04)
; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; During the last decades, seismic monitoring experienced important advances by introducing small aperture arrays and dense seismic networks equipped with high-dynamic-range instrumentation. This new recording reality allowed to lower significantly the monitoring threshold, to identify in quasi real time active seismo-tectonic structures and to reveal information about the seismic source and its rupture dynamics. The application of array techniques, as beamforming and f-k analysis use the coherence properties of the recorded wavefield for increasing the S/N-ratio, to determine back-azimuth and apparent velocity of the incoming wavefield and to automatically locate the seismic events of small magnitudes. We realized the first permanent small aperture array installation in Italy, called CISA (Central Italy Seismic Array) composed of 9 three-component seismic sensors installed at interstation distances from 100 - 500 m and a maximal extension of 1000 m. CISA's circular configuration and its geographical position is aimed to monitor the microseismicity of Central Italy at a local and regional range, including the epicentral area of the 2016/17 seismic sequence, as well as the geothermal areas in the western sector. CISA's challenges are to decrease the detection threshold of the microseismicity, to identify active faults in Umbria by analysis of the microseismicity and to study in detail the rupture dynamics of moderate earthquakes, by using source scan algorithm.Seismic data are transmitted in real-time to the data center of SARA-electronic (Perugia) by ordinary 4G-LTE router and then forwarded to the observatories of Arezzo and Munich by using seedlink protocol. An ObsPy module manages the fk-detection, calculating in real-time backazimuth, slowness, gain and semblance. On a local scale CISA is expected to operate in a magnitude range from 099 22 - PublicationOpen AccessProgetto per la misura, raccolta e trasmissione di dati di emissione radon per stazioni sismiche multiparametriche(2020-04-01)
; ; ; ; ; ; ; ; ; ; ; ; ; The seismic monitoring of the national territory and of the EuroMediterranean area makes use of the velocimetric, accelerometric and GPS (geodetic) data acquired by the stations of the National Seismic Network, by the RING Network and by the MedNet Network. As part of the FISR 2017 project “Integrated operating rooms and monitoring networks for the future: INGV 2.0” (2017), sensors capable of detecting both geophysical and geochemical parameters at the same time are being integrated. This technical report describes the integration of a Rn222 sensor (radon hereafter). Over the past few decades radon has found a variety of Earth Science applications, ranging from its use as a potential earthquake precursor and tectonic stress indicator to its specific role in volcanic environments, where significant changes in concentration previous or concomitant to eruptive crises are also induced by volcanic gases, CO 2 for example, which act as carriers accelerating the migration of radon through the earth’s crust and therefore its detection. In order to explore the possibility of a link between seismogenic processes and temporal variability of radon emissions, a permanent national network has been created, IRON (Italian Radon mOnitoring Network), which uses both commercial radon instruments, equipped with a proprietary system for data storage, transmission and consultation, and INGV sensors that need an interface to acquire and make data available remotely. A hardware and software interface has therefore been designed, built and tested capable of i) counting and storing the pulses in TTL format generated by the instrument which measures the 8 radon concentration in air, ii) being connected to a router for sending the acquired data to a server. A service (syncproc) was also created in PHP to query remote stations at regular intervals and collect the acquired data intended to populate a database created with MariaDB. An expressly created website allows to extract the stored data from the database and configure each installed sensor. The various software elements have been designed using open source resources.105 10 - PublicationRestrictedOrologio Digitale GPS con generazione del marcatempo(2009-12-01)
; ; ;Rao, Sandro; Istituto Nazionale di Geofisica e Vulcanologia, Sezione CNT, Roma, Italia ;Thorossian, William; Istituto Nazionale di Geofisica e Vulcanologia, Sezione CNT, Roma, Italia; 146 13 - PublicationOpen AccessProgetto HeliDAC(2012)
; ; ; ; ; ; ; ; ; ; ; Sistema di conversione digitale analogico per la visualizzazione dei segnali sismici su Helicorder86 26 - PublicationOpen AccessNoise Field Characteristics of a Seismic Small Aperture Array Installation in Central Italy(2019-07-08)
; ; ; ; ; ; ; ; ; ; ; ; ;; ; The realization of the first permanent seismic small-scale array in Central Italy is aimed to monitor the micro-seismicity at a local and regional range, including the epicentral area of the 2016-18 seismic sequence and also the geothermal areas in the western sector. The array called CISA (Central Italy Seismic Array) has a maximum aperture of 1000 m and is composed of 9 three-component seismic sensors installed at inter-station distances between 100 and 500m. When designing a seismic array, the number of sensors, their respective inter-station distances and the array aperture must be tuned to the wavenumber characteristics of the target signals and the local noise field, in order to optimize the signal-to-noise ratio. For this purpose, the statistical structure of signal and noise have been analyzed by means of auto-correlation and cross-correlation functions for all combinations of sensor pairs in order to determine suitable interstation distances, such that the array response-once tuned to the signal-suppresses energy reaching the array with wavenumbers, which are characteristic for the local noise wave-field. The Rayleigh-wave dispersion curve retrieved combining results of auto-correlation and frequency-wavenumber analysis on ambient noise data, has also been inverted by using a neighborhood algorithm in order to retrieve the shear-wave velocity profile for the site down to a depth proportional to the spatial configuration of the array.88 27 - PublicationOpen AccessFirst results of CISA, the new Central Italy Seismic Array(2019-07)
; ; ; ; ; ; ; ; ; ; ; ; ; During the last decades, seismic monitoring experienced important advances by introducing small aperture arrays and dense seismic networks equipped with high-dynamic-range instrumentation. This new recording reality allowed to lower significantly the monitoring threshold, to identify in quasi real time active seismo-tectonic structures and to reveal information about the seismic source and its rupture dynamics. The application of array techniques, as beamforming and f-k analysis use the coherence properties of the recorded wavefield for increasing the S/N-ratio, to determine back-azimuth and apparent velocity of the incoming wavefield and to automatically locate the seismic events of small magnitudes. We realized the first permanent small aperture array installation in Italy, called CISA (Central Italy Seismic Array) composed of 9 three-component seismic sensors installed at interstation distances from 100 - 500m and a maximal extension of 1000m. CISA’s circular configuration and its geographical position is aimed to monitor the microseismicity of Central Italy at a local and regional range, including the epicentral area of the 2016/17 seismic sequence, as well as the geothermal areas in the western sector. CISA’s challenges are to decrease the detection threshold of the microseismicity, to identify active faults in Umbria by analysis of the microseismicity and to study in detail the rupture dynamics of moderate earthquakes, by using source scan algorithm. Seismic data are transmitted in real-time to the data center of SARA-electronic (Perugia) by ordinary 4G-LTE router and then forwarded to the observatories of Arezzo and Munich by using seedlink protocol.102 24 - PublicationOpen AccessUN GENERATORE DI PETTINE DI FREQUENZE PER L’ECCITAZIONE DI RIVELATORI DI FOTONI A BASSA ENERGIA(2012)
; ; ; ; ;Iarocci, Alessandro; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia ;Thorossian, William; Istituto Nazionale di Geofisica e Vulcanologia, Sezione CNT, Roma, Italia ;Benedetti, Paolo; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia ;Romeo, Giovanni; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia; ; ; Il lavoro qui presentato, che nasce dalla collaborazione tra l’LNTS (Laboratorio Nuove Tecnologie e Strumenti) dell’INGV e il Dipartimento di Fisica dell’Università di Roma “La Sapienza”, descrive lo strumento realizzato per fornire il pettine di frequenze atto ad eccitare un sistema sperimentale per otto risuonatori KID. In tale sistema il pettine di frequenze verrà traslato nella banda di frequenza dei KIDs (nell’ordine dei GHz) per poterne effettuare l’eccitazione e quindi riportato nella banda iniziale per effettuarne l’acquisizione e l’analisi.303 140 - PublicationOpen AccessCaratteristiche del campo d’onda del rumore sismico di un’installazione array in Italia Centrale(2019-11-12)
; ; ; ; ; ; ; ; ; ; ; ;; Grazie ai finanziamenti ottenuti attraverso il bando di ricerca libera proposto all’interno dell’INGV (0865.039 FISR 2016), a partire da Maggio 2018 è operativo nel centro Italia un’array sismico a piccola scala. L’obiettivo è quello di monitorare la microsismicità locale e regionale, inclusa la sequenza sismica del centro Italia 2016-2018 e le aree geotermiche site ad ovest della zona che ospita l’esperimento. L’array, che prende il nome di CISA (Central Italy Seismic Array), ha un’apertura massima di 1000 metri ed è composto da 9 stazioni con sensori velocimetrici a 3 componenti installati ad una distanza reciproca compresa tra 100 e 500 metri. In fase di progettazione di un array in termini di apertura massima e distanza inter-stazione, è bene tenere in mente le caratteristiche del segnale target e studiare il campo d’onda del rumore locale, per ottimizzare il rapporto segnale/rumore. A questo scopo, sono state analizzate le caratteristiche statistiche del segnale e del rumore ambientale in termini di funzioni di autocorrelazione e cross-correlazione per tutte le combinazioni di coppie di stazioni. In questo modo è possibile determinare la distanza inter-stazione più adatta, così che la risposta dell’array, una volta ottimizzato il segnale registrato, possa sopprimere il contributo di energia ascrivibile al campo d’onda del rumore locale. È stata inoltre calcolata la curva di dispersione combinando i risultati dell’analisi di autocorrelazione con quelli ricavati dall’applicazione della tecnica fk sui dati di rumore ambientale. La curva così ottenuta è stata invertita, utilizzando il metodo neighbourhood algorithm per ricavare il profilo di velocità delle onde S del sito fino ad una profondità proporzionale alla configurazione spaziale dell’array99 28