171,132 research outputs found
Autoscala applied at the Ionospheric Station of Warsaw
No full textA new ionosonde VISRC2, built at the Space Research Center of Warsaw, Poland, was installed at Warsaw (52.2 N, 21.1 E) in march 2007. The main characteristics of this ionosonde are: transmitted power 10 kW, pulse duration 100 μs, sampling period 5 μs, frequency resolution 25 kHz, and capability to distinguish ordinary and extraordinary reflections.
This ionosonde, able to record the sounding only as a binary file, was not equipped with a tool to perform an automatic scaling of the recorded trace.
From October 2008 Autoscala (Pezzopane and Scotto, 2005, 2007, 2008; Scotto and Pezzopane, 2007) is routinely applied to the ionograms recorded by this ionosonde.Published1.7. Osservazioni di alta e media atmosfera3.9. Fisica della magnetosfera, ionosfera e meteorologia spazialeN/A or not JCRope
Estimation of probability of occurrence of F1 layer or L condition using tables and electron density profile models
No full textAn algorithm is proposed for evaluation of the probability of occurrence of an F1 layer or L condition, based on tables. Observations independent of the tables database are used for comparison between the estimated probability of occurrence, the formulation used at present in IRI, and the occurrence actually observed. The importance of the inclusion of L condition in the electron density profile model is shown.Published2053-20563.9. Fisica della magnetosfera, ionosfera e meteorologia spazialeJCR Journalreserve
Electron density profile calculation technique for Autoscala ionogram analysis
No full textAn electron density profile model with free parameters is introduced. Initially the parameters are calculated on the basis of the ionospheric characteristics automatically obtained from the ionograms by Autoscala and considering the helio-
geophysical conditions. The technique used to adjust the free parameters to the particular ionograms recorded is presented.Published756-7661.7. Osservazioni di alta e media atmosfera3.9. Fisica della magnetosfera, ionosfera e meteorologia spaziale5.4. Banche dati di geomagnetismo, aeronomia, clima e ambienteJCR Journalreserve
Sporadi-E layer and metereological activity
No full textObscrvations of Es laycr performed at the ionospheric observatory of Rome from 1982 to 1989 have been used to investigate a possible correlation with cold front passages. Such a correlation may exist because of the AGW excited by tropospheric activity at cold front passages. A relationship with thunderclouds electrostatic field is also marginally considered. The treatment of data shows that the distributions of the frequencies of renection at cold front passages present only small differences compared to normal days, both for the f and for the I type; therefore, a correlation between Es layer anù meteorological activity cannot be affirmed
A method for automatic scaling of F1 critical frequencies from ionograms
No full textThis work describes a method that has been developed to automatically assess
whether the F1 layer is present or not on an ionogram trace, and, if present, to scale the
F1 critical frequency foF1. The ionograms in which the information related to the F1 trace
is insufficient are identified and considered separately. In order to test the performance of
this method and the conditions in relation to which it could be improved, a data set of
ionograms recorded from September 2005 to June 2006 by the AIS-INGV ionosonde
installed at Rome was used. The values obtained automatically by Autoscala, with the
addition of this new F1 layer routine, were compared with those obtained by the standard
manual method.PublishedRS2S911.7. Osservazioni di alta e media atmosfera3.9. Fisica della magnetosfera, ionosfera e meteorologia spazialeJCR Journalreserve
Highlighting the F2 trace on an ionogram to improve Autoscala performance
No full textThis work describes a linear regression based method for highlighting the cuspidal trace on an ionogram. This method was initially thought to smooth out cases in which the autoscaling of the ionogram performed by Autoscala was erroneous because the F2 ordinary ray was identified as the extraordinary ray. Actually the development of this method turned out to also be very useful for filtering out noise and assisting the main algorithm of Autoscala to not be misled by multiple-hop sporadic E layer echoes. Applying the algorithm to different ionograms recorded by different ionosondes showed that the application of this method considerably improved the Autoscala performance. The role that this method plays in the light of existing algorithms is also discussed.Published1168-11771.7. Osservazioni di alta e media atmosfera3.9. Fisica della magnetosfera, ionosfera e meteorologia spazialeJCR Journalope
Le poème-médita(c)tion
No full textL'articolo si propone di indagare, attraverso la lettura di alcuni testi poetici e interviste ritenuti fondamentali, la poetica di André Velter, scrittore, viaggiatore, editore, poeta, evidenziando in essa un duplice movimento di uscita da sé e di ritorno a sé che l'erranza fisica e intellettuale favorisce. In essa ogni gesto mentale prelude ad un'azione che può anche rivelarsi, in un senso laicamente mistico, una sorta d'inazione che dell'azione riconosce l'inanità, ma non l'intento che l'ha determinata, il quale comunque modifica lo stato di partenza. In tal modo l'effusione dell'erranza tratteggia un percorso di conoscenza che è anche un esercizio di "dépense" convocante esperienze, presenze, un'intera e variegata comunità degli animi associata a un rito energetico di aggregazione fisica e intellettuale
The effect of collisions in ionogram inversion
No full textThe results of this paper demonstrate that the effect of collisions on the group refraction index is small, when the ordinary ray is considered. If, however, in order to improve the performance of a system for automatic interpretation of ionograms, the information contained in ordinary and extraordinary traces is combined, the effect of collisions between the electrons and neutral molecules should be taken into account for the extraordinary ray. The magnitude of these differences is generally very small and must be compared with the resolution in the virtual vertical height of the ionosonde, resolution which is typically of the order of few kilometers.Published697-7011.7. Osservazioni di alta e media atmosfera3.9. Fisica della magnetosfera, ionosfera e meteorologia spazialeJCR Journalrestricte
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