122 research outputs found
Tecniche radio per investigare la ionosfera terrestre
No full textNel seminario vengono presentate in modo generale le principali tecniche sperimentali di investigazione della ionosfera terrestre.
Per ognuna di esse sono descritti gli elementi su cui si basa, pregi, difetti e le grandezze ionosferiche oggetto delle loro misure.
Vengono presentate, poi, tre tecniche in modo approfondito, utilizzate anche nelle attività sperimentali dell'Istituto Nazionale di Geofisica e Vulcanologia: sondaggio verticale, riometro e GPS per scintillazioni.UnpublishedDipartimento di Fisica dell'Universita' "La Sapienza" di Roma1.7. Osservazioni di alta e media atmosfera3.9. Fisica della magnetosfera, ionosfera e meteorologia spaziale5.8. TTC - Formazione e informazioneope
Tecniche radio per investigare la ionosfera terrestre
No full textNel seminario vengono presentate in modo generale le principali tecniche sperimentali di investigazione della ionosfera terrestre.
Per ognuna di esse sono descritti gli elementi su cui si basa, pregi, difetti e le grandezze ionosferiche oggetto delle loro misure.
Vengono presentate, poi, tre tecniche in modo approfondito, utilizzate anche nelle attività sperimentali dell'Istituto Nazionale di Geofisica e Vulcanologia: sondaggio verticale, riometro e GPS per scintillazioni.UnpublishedDipartimento di Fisica dell'Universita' "La Sapienza" di Roma1.7. Osservazioni di alta e media atmosfera3.9. Fisica della magnetosfera, ionosfera e meteorologia spaziale5.8. TTC - Formazione e informazioneope
Coerenza: A software tool for computing the maximum coherence times of the ionosphere
No full textPower–height (PH) observations of the radio echo reflected from the ionosphere were performed every
15 min at a frequency of 3 MHz at the Rome ionospheric observatory, during the period 3–22 January
2008. This work describes software that can calculate the maximum coherence times of the ionosphere
from PH data. The applications for this software are also discussed.Published1504-15113.9. Fisica della magnetosfera, ionosfera e meteorologia spazialeJCR Journalrestricte
L'uso della polarizzazione dell'eco nei sondaggi ionosferici
No full textWhile performing an ionospheric sounding
the information brought by the polarisation
of the received echo is not essential. In fact, the
"AIS" ionosonde [Arokiasami 2002], developed
at INGV in the recent years, does not allow for
this piece of information but it is able to generate
good quality ionograms, from which it is
possible to discriminate between the ordinary
and the extraordinary ray. Anyway, if the polarisation
information is available the automatic
scaling of the ionograms can be more effective.
This work consists of some theoretical and technological
considerations, fundamental to the
development of an improved ionosonde model,
that has been carried on at INGV. The magnetoionic
theory of propagation of radio waves
into the ionosphere is assumed as known; so
only some concepts concerning more tightly the
waves polarisation and the creation of the ordinary
and the extraordinary rays are developed;
eventually the practical ways by which it is possible
to discriminate them by means of a sounding
instrument are described.Published1-151.7. Osservazioni di alta e media atmosfera3.9. Fisica della magnetosfera, ionosfera e meteorologia spazialeN/A or not JCRope
Interfacing and off-line analysis for VOS-1A Barry ionosonde
No full textIonospheric studies have a great importance in radiopropagation and planetary atmospheric physics. The basic instrument for the investigation of ionospheric physics is the sweep frequency H-F radar called ionosonde. Ionospheric measurements, like other geophysical quantities, are useful only if there is a long and unbroken history, both for scientific and service purposes. Therefore a huge amount of data is produced and only a few ionospheric characteristics are scaled. In the Istituto Nazionale di Geofisica, the ionospheric hard copy data bank (paper and film) already requires a large storage space. The rough data on hard copy are not suitable for complete analysis and they should be completely digitized before processing. Usually only some characteristics are digitized and stored (scaled ionogram), but in this way it becomes more difficult to extract important physical quantities like the electron density profile. In order to overcome these problems, an Ionospheric Data Acquisition System (IDAS) based on commercial PCs has been developed. This ensures reliability for data acquisition and the availability of commercial software packages for analysis, compression and storage.JCR Journalope
La ionosfera: comunicare... naturalmente!
No full textSi tratta della terza Geopagina della collana del TTC "Formazione e Informazione"La ionosfera è la parte della media-alta atmosfera compresa tra i 60 e i 1000 km di quota. Essa è caratterizzata da una concentrazione di elettroni tale da modificare la propagazione delle onde radio che la attraversano.Published5.8. TTC - Formazione e informazioneope
L'uso della polarizzazione dell'eco nei sondaggi ionosferici
No full textWhile performing an ionospheric sounding
the information brought by the polarisation
of the received echo is not essential. In fact, the
"AIS" ionosonde [Arokiasami 2002], developed
at INGV in the recent years, does not allow for
this piece of information but it is able to generate
good quality ionograms, from which it is
possible to discriminate between the ordinary
and the extraordinary ray. Anyway, if the polarisation
information is available the automatic
scaling of the ionograms can be more effective.
This work consists of some theoretical and technological
considerations, fundamental to the
development of an improved ionosonde model,
that has been carried on at INGV. The magnetoionic
theory of propagation of radio waves
into the ionosphere is assumed as known; so
only some concepts concerning more tightly the
waves polarisation and the creation of the ordinary
and the extraordinary rays are developed;
eventually the practical ways by which it is possible
to discriminate them by means of a sounding
instrument are described.Published1-151.7. Osservazioni di alta e media atmosfera3.9. Fisica della magnetosfera, ionosfera e meteorologia spazialeN/A or not JCRope
Sporadic E layer at mid-latitudes: average properties and influence of atmospheric tides
No full textThis paper describes a study of the daily variability shown by the main
characteristics of the sporadic E (Es) layer, that is the top frequency
(ftEs) and the lowest virtual height (h'Es). The study is based on ionograms
recorded by the Advanced Ionospheric Sounder by the Istituto Nazionale di Geofisica e Vulcanologia
(AIS-INGV) ionosondes installed in the ionospheric stations at
Rome (41.8° N, 12.5° E) and Gibilmanna (37.9° N,
14.0° E), Italy, during the summer (June, July, August and September) of 2013,
a year falling in the ascending phase of solar cycle 24. The ftEs presents a diurnal variation characterized
by two maxima, the first around noon is very well defined and the second
in the evening/night is much less defined; the amplitude of both maxima
decreases from June to September accompanied by a general decrease of the
ftEs values which is more pronounced in the daytime than in the nighttime.
h'Es also presents a diurnal variation characterized by two maxima but,
unlike ftEs, these present the same amplitude which is independent from the
considered month. Assuming that both ftEs and h'Es trends are influenced by
the atmospheric tides, the height–time–intensity (HTI) technique was applied
to deeply investigate how these waves control the Es dynamics. The HTI study,
along with a fast Fourier transform analysis, show that a well-defined
semidiurnal periodicity characterizes the Es layer dynamics most accurately in June
and July, while in August and September the daytime semidiurnal periodicity
becomes weaker and the role of the diurnal periodicity is consequently
highlighted
Commento all'art. 26 Testo unico dell'Edilizia
No full textIl contributo esamina, attraverso il richiamo dei precedenti giurisprudenziali più significativi e dei diversi orientamenti dottrinali, la dichiarazione di inagibilità, soffermandosi, in particolare, sulla competenza e sui presupposti per la relativa adozione
Ionospheric vertical radio soundings
No full textThe presentation deals with one of the most popular technique to investigate the terrestrial ionosphere: the
vertical radio sounding.
The basic elements of the radar theory are explained starting from the envelope radar up to the most sophisticated techniques of the coded radars.
Antennas design elements and problems are highlighted along with the most common solutions.
Then the principles of the ionospheric measurements are reported from the ionogram to the ionospheric parameters and to the density profile.
A real example of a geomagnetic storm is also presented.Published"Campus Reiss Romoli" COPPITO L’AQUILA (ITALY)1.7. Osservazioni di alta e media atmosfera3.9. Fisica della magnetosfera, ionosfera e meteorologia spazialeope
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