ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • 01. Atmosphere::01.02. Ionosphere::01.02.06. Instruments and techniques  (48)
  • 04. Solid Earth::04.04. Geology::04.04.09. Structural geology
  • 04. Solid Earth::04.06. Seismology::04.06.07. Tomography and anisotropy
  • 04. Solid Earth::04.07. Tectonophysics::04.07.06. Subduction related processes
  • INGV  (53)
  • Agu  (6)
  • Nature Publishing Group  (3)
  • Public Library of Science (PLoS)
Collection
Keywords
Publisher
Years
  • 1
    facet.materialart.
    Unknown
    An interhemispheric comparison of GPS phase scintillation with auroral emission observed at the South Pole and from the DMSP satellite (2013)
    INGV
    Details
    Publication Date: 2020-12-03
    Description: The global positioning system (GPS) phase scintillation caused by highlatitude ionospheric irregularities during an intense high-speed stream (HSS) of the solar wind from April 29 to May 5, 2011, was observed using arrays of GPS ionospheric scintillation and total electron content monitors in the Arctic and Antarctica. The one-minute phase-scintillation index derived from the data sampled at 50 Hz was complemented by a proxy index (delta phase rate) obtained from 1-Hz GPS data. The scintillation occurrence coincided with the aurora borealis and aurora australis observed by an all-sky imager at the South Pole, and by special sensor ultraviolet scanning imagers on board satellites of the Defense Meteorological Satellites Program. The South Pole (SP) station is approximately conjugate with two Canadian High Arctic Ionospheric Network stations on Baffin Island, Canada, which provided the opportunity to study magnetic conjugacy of scintillation with support of riometers and magnetometers. The GPS ionospheric pierce points were mapped at their actual or conjugate locations, along with the auroral emission over the South Pole, assuming an altitude of 120 km. As the aurora brightened and/or drifted across the field of view of the all-sky imager, sequences of scintillation events were observed that indicated conjugate auroras as a locator of simultaneous or delayed bipolar scintillation events. In spite of the greater scintillation intensity in the auroral oval, where phase scintillation sometimes exceeded 1 radian during the auroral break-up and substorms, the percentage occurrence of moderate scintillation was highest in the cusp. Interhemispheric comparisons of bipolar scintillation maps show that the scintillation occurrence is significantly higher in the southern cusp and polar cap.
    Description: Published
    Description: R0216
    Description: 1.7. Osservazioni di alta e media atmosfera
    Description: 3.9. Fisica della magnetosfera, ionosfera e meteorologia spaziale
    Description: JCR Journal
    Description: open
    Keywords: Scintillations ; Solar-terrestrial interaction ; Space weather ; Solar variability and solar wind ; Magnetic storms ; 01. Atmosphere::01.02. Ionosphere::01.02.99. General or miscellaneous ; 01. Atmosphere::01.02. Ionosphere::01.02.05. Wave propagation ; 01. Atmosphere::01.02. Ionosphere::01.02.06. Instruments and techniques ; 01. Atmosphere::01.02. Ionosphere::01.02.07. Scintillations ; 05. General::05.07. Space and Planetary sciences::05.07.02. Space weather
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 2
    facet.materialart.
    Unknown
    On the relevance of Born theory in global seismic tomography (2007)
    Agu
    Details
    Publication Date: 2021-01-27
    Description: Does the application of seismic Born theory, as opposed to simpler ray theory, lead to an improvement in tomographic images of the Earth? In recent publications, Montelli et al. (2004a, 2004b) and van der Hilst and de Hoop (2005) among others have expressed opposite opinions. We propose a quantitative approach to the comparison of tomographic images, which we apply to the case of surface-wave phase velocity maps derived with Born vs. ray theory.
    Description: Published
    Description: L06302
    Description: JCR Journal
    Description: reserved
    Keywords: global seismic tomography ; 04. Solid Earth::04.06. Seismology::04.06.07. Tomography and anisotropy
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 3
    facet.materialart.
    Unknown
    Scintillations effects on satellite to Earth links for telecommunication and navigation purposes (2006)
    INGV
    Details
    Publication Date: 2021-05-17
    Description: Radio wave scintillations are rapid fluctuations in both amplitude and phase of signals propagating through the atmosphere. GPS signals can be affected by these disturbances which can lead to a complete loss of lock when the electron density strongly fluctuates around the background ionization level at small spatial scales. This paper will present recent improvements to the theoretical Global Ionospheric Scintillation Model (GISM), particularly tailored for satellite based navigation systems such GPS coupled with Satellite Based Augmentation System (SBAS). This model has been improved in order to take into account GPS constellation, signals, and receiver response to ionospheric scintillation environments. A new modelling technique, able to describe the scintillation derived modifications of transionospheric propagating fields is shown. Results from GPS derived experimental measurements performed at high and low magnetic latitudes will show preliminary assessments of the scintillation impact on real receivers and system operations. Nevertheless, comparisons between theoretical scintillation models, such as WBMOD and GISM, with GPS derived experimental data will be shown.
    Description: Published
    Description: JCR Journal
    Description: open
    Keywords: 01. Atmosphere::01.02. Ionosphere::01.02.06. Instruments and techniques
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Format: 2603241 bytes
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 4
    facet.materialart.
    Unknown
    A different approach to the analysis of GPS scintillation data (2006)
    INGV
    Details
    Publication Date: 2021-05-17
    Description: Amplitude scintillation data from GPS were analyzed. The objective is to estimate the impact of ionospheric scintillations at Satellite Based Augmentation Systems Ranging and Integrity Monitoring Station (SBAS RIMS) level and at GPS user level. For this purpose, a new approach to the problem was considered. Data were studied from the point of view of the impact of scintillations on the calculation of VTEC at pierce points and ionospheric grid points. An ionospheric grid of 5° 5° surface squares was assumed. From geometrical considerations and taking into account the basic principle to compute VTEC at grid points, with the data analyzed it is shown that scintillations very seldom affect the calculation of a grid point VTEC. Data from all the RIMS and for the entire GPS satellites network must be analyzed simultaneously to describe a realistic scenario for the impact of scintillations on SBAS. Finally, GPS scintillation data were analyzed at user level: service availability problems were encountered.
    Description: Published
    Description: JCR Journal
    Description: open
    Keywords: ionospheric scintillations ; GPS scintillation monitor ; SBAS ; 01. Atmosphere::01.02. Ionosphere::01.02.06. Instruments and techniques
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Format: 128704 bytes
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 5
    facet.materialart.
    Unknown
    GPS scintillations and total electron content climatology in the southern low, middle and high latitude regions (2013)
    INGV
    Details
    Publication Date: 2020-12-14
    Description: 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.
    Description: Published
    Description: R0220
    Description: 1.7. Osservazioni di alta e media atmosfera
    Description: 3.9. Fisica della magnetosfera, ionosfera e meteorologia spaziale
    Description: JCR Journal
    Description: open
    Keywords: Scintillations ; Dynamics ; Solar-terrestrial interaction ; Space weather ; Statistical analysis ; 01. Atmosphere::01.02. Ionosphere::01.02.05. Wave propagation ; 01. Atmosphere::01.02. Ionosphere::01.02.06. Instruments and techniques ; 01. Atmosphere::01.02. Ionosphere::01.02.07. Scintillations ; 05. General::05.07. Space and Planetary sciences::05.07.02. Space weather
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 6
    facet.materialart.
    Unknown
    eSWua: a tool to manage and access GNSS ionospheric data from mid-to-high latitudes (2013)
    INGV
    Details
    Publication Date: 2021-06-16
    Description: The electronic space weather upper atmosphere (eSWua) is a hardware– software system that is based on measurements collected by instruments installed by the Upper Atmosphere Physics Group of the Istituto Nazionale di Geofisica e Vulcanologia (INGV, Italy). More recently, it has also included the Global Navigation Satellite System (GNSS) ionospheric scintillation and total electron content (TEC) monitor (GISTM) stations 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. Web access to the data and tools has been realized to handle the data from the sites at low, mid and high latitudes. In this report, we present the results of the system for the GNSS data in the Arctic, the Antarctica, and the three GISTM stations operated by the University of Nottingham: Nottingham, Trondheim and Dourbes. Case studies of the efficacy of this system for scientific and application purposes are also presented and discussed.
    Description: Published
    Description: R0223
    Description: 1.7. Osservazioni di alta e media atmosfera
    Description: 5.4. Banche dati di geomagnetismo, aeronomia, clima e ambiente
    Description: JCR Journal
    Description: open
    Keywords: Database ; GNSS ; Global positioning system ; Ionosphere ; Total electron content ; Ionospheric scintillation ; 01. Atmosphere::01.02. Ionosphere::01.02.06. Instruments and techniques ; 01. Atmosphere::01.02. Ionosphere::01.02.07. Scintillations ; 05. General::05.01. Computational geophysics::05.01.01. Data processing ; 05. General::05.02. Data dissemination::05.02.05. Collections
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 7
    facet.materialart.
    Unknown
    An example of operation for a partly manned Antarctic geomagnetic observatory and the development of a radio link for data transmission (2009)
    INGV
    Details
    Publication Date: 2017-04-04
    Description: The experience acquired from more than ten years of operation of an Antarctic geomagnetic observatory is described along with the development of data transmission facilities. The observatory was deployed at the Spanish Antarctic Station in 1996. The main instrument was an Overhauser magnetometer deployed in dual axis Helmholtz coils, a δD/δI configuration. The site is only manned during the summer, with the magnetometer left recording throughout the rest of the year. During the 2007-2008 survey the observatory instrumentation has been upgraded with a DMI suspended triaxial fluxgate magnetometer, new sampling hardware and data logging software. Both sampling and timing are carried out under the control of a PIC based microcontroller and GPS receiver. Data presentation, transmission and archiving are performed under the control of a low power embedded PC. For real time access to the data two options have been provided and rigorously tested during the last 10 years: METEOSAT and GOES Data Collection Systems, and recently, a high frequency (HF) digital radio-link, using ionospheric propagation between Antarctica and Spain, has been developed. This latest transmission system is being continuously upgraded, and it would be possible to extend its application to other remote stations. Measurements have been made during the last four years in order to determine the channel characteristics and its variability, mainly the multipath and Doppler spread and the link availability for a given SNR in the receiver. These measurements are being used to design the physical layer of a radiomodem intended to maximize the link capacity keeping the emitted power low.
    Description: Published
    Description: 45-56
    Description: 1.6. Osservazioni di geomagnetismo
    Description: 2.6. TTC - Laboratorio di gravimetria, magnetismo ed elettromagnetismo in aree attive
    Description: JCR Journal
    Description: open
    Keywords: geomagnetic observatories ; geophysical instrumentation ; data transmission ; HF radio ; 01. Atmosphere::01.02. Ionosphere::01.02.06. Instruments and techniques ; 04. Solid Earth::04.05. Geomagnetism::04.05.08. Instruments and techniques
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 8
    facet.materialart.
    Unknown
    Tomomorphometry of the Somma-Vesuvius volcano (Italy) (2007)
    Agu
    Details
    Publication Date: 2017-04-04
    Description: A tomomorphometric analysis of the Somma-Vesuvius topography is presented. This consists in extracting horizontal cross sections at different altitudes, and in determining some morphometric parameters: radius of the circle with a surface area equal to the cross section, circularity, ratio between the major and minor axis of the best fitting ellipse, orientation a of the ellipse major axis, and the x-y centroid. The Somma includes three portions: the apron zone, the flanks, and the summit caldera boundary. Between 225 m and 525 m, a is 50 –60 . Between 600 m and 775 m, a is 130 –135 . These are the preferred strike of the eruptive fissures affecting the northwestern Somma flanks, the faults affecting the whole edifice, the nodal planes from local earthquakes. The Somma activity developed along a NE-SW structural discontinuity, whereas the post-caldera activity concentrated along a NW-SE striking structure. Somma activity migrates from SE to NW.
    Description: Published
    Description: L17305
    Description: JCR Journal
    Description: reserved
    Keywords: Tomomorphometry ; Somma-Vesuvius volcano ; 04. Solid Earth::04.04. Geology::04.04.03. Geomorphology ; 04. Solid Earth::04.04. Geology::04.04.09. Structural geology
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 9
    facet.materialart.
    Unknown
    Compressional velocity structure and anisotropy in the uppermost mantle beneath Italy and surrounding regions (2007)
    Agu
    Details
    Publication Date: 2017-04-04
    Description: Travel times of about 39,000 Pn arrivals recorded from regional earthquakes by the Italian Telemetered Seismic Network and by stations of nearby countries are inverted to image lateral variations of seismic velocity and anisotropy at subcrustal depth in Italy and surrounding regions. This method allows simultaneous imaging of variations of Pn velocity and anisotropy, as well as crustal thickness variations. The Po plain, the Adriatic Sea, and the Ionian Sea have normal to high Pn velocities. In contrast, lower velocities (7.9-8.0 km/s) are imaged in Italy beneath the western Alps, the northern Apennines, and eastern Sicily and nearby Calabria, as well as in northern Albania and beneath the Pannonian basin. Low Pn velocities beneath the northern Apennines correlate with present-day extension and may have resulted from thermal anomalies in the uppermost mantle due to delamination processes. Low velocities are consistent with the high-attenuation zone inferred in the uppermost mantle beneath the internal Apennine units and the Tyrrhenian margin of the peninsula by Mele et al. [1996, 1997]. On the contrary, low velocities beneath the western Alps may be an apparent effect due to the abrupt thickening of the crustal roots. Pn velocity is anisotropic in the study area with a maximum amplitude of ± 0.2 km/s. The largest anisotropic velocity anomalies are observed along the major arc structures of Italy, i.e., the northern Apennines and the Calabrian Arc, indicating that these features are controlled by uppermost mantle processes. The anisotropy anomaly along the Calabrian Arc extends as far as Albania but ends abruptly north of this area, suggesting that a lithospheric discontinuity is present along the northern Albanian border.
    Description: Published
    Description: 12,529-12,543
    Description: JCR Journal
    Description: reserved
    Keywords: Pn anisotropic tomography ; Italy ; 04. Solid Earth::04.06. Seismology::04.06.07. Tomography and anisotropy
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 10
    facet.materialart.
    Unknown
    Mapping mantle flow during retreating subduction: Laboratory models analyzed by feature tracking (2007)
    Agu
    Details
    Publication Date: 2017-04-04
    Description: Three-dimensional dynamically consistent laboratory models are carried out to model the large-scale mantle circulation induced by subduction of a laterally migrating slab. A laboratory analogue of a slab–upper mantle system is set up with two linearly viscous layers of silicone putty and glucose syrup in a tank. The circulation pattern is continuously monitored and quantitatively estimated using a feature tracking image analysis technique. The effects of plate width and mantle viscosity/density on mantle circulation are systematically considered. The experiments show that rollback subduction generates a complex three-dimensional time-dependent mantle circulation pattern characterized by the presence of two distinct components: the poloidal and the toroidal circulation. The poloidal component is the answer to the viscous coupling between the slab motion and the mantle, while the toroidal one is produced by lateral slab migration. Spatial and temporal features of mantle circulation are carefully analyzed. These models show that (1) poloidal and toroidal mantle circulation are both active since the beginning of the subduction process, (2) mantle circulation is intermittent, (3) plate width affects the velocity and the dimension of subduction induced mantle circulation area, and (4) mantle flow in subduction zones cannot be correctly described by models assuming a two-dimensional steady state process. We show that the intermittent toroidal component of mantle circulation, missed in those models, plays a crucial role in modifying the geometry and the efficiency of the poloidal component
    Description: Published
    Description: B03402
    Description: JCR Journal
    Description: reserved
    Keywords: mantle flow ; subduction ; 04. Solid Earth::04.07. Tectonophysics::04.07.01. Continents ; 04. Solid Earth::04.07. Tectonophysics::04.07.06. Subduction related processes
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...