Peer-reviewed articles 17,970 +



Title: AN EMPIRICAL MODEL FOR FORECASTING THE CRITICAL FREQUENCY OF THE IONOSPHERIC E-REGION OVER BULGARIA

AN EMPIRICAL MODEL FOR FORECASTING THE CRITICAL FREQUENCY OF THE IONOSPHERIC E-REGION OVER BULGARIA
R. Bojilova; P. Mukhtarov
1314-2704
English
21
1.1
• Prof. DSc. Oleksandr Trofymchuk, UKRAINE
• Prof. Dr. hab. oec. Baiba Rivza, LATVIA
This work presents an empirical model for forecasting the hourly values of the
ionospheric E-region critical frequency (foE) over Bulgaria in dependence of both: the
index of the solar activity described by F10.7 and the cosine of solar zenith angle. The
dependence of foE on solar activity and solar zenith angle is studied by correlation and
regression analysis. The obtained relationships are used as a base for the synthesis of the
model. The model is produced by using the hourly values of foE obtained in the
ionospheric station Sofia. It allows predicting the respective foE values in the absence
of fresh data from the vertical sounding of the ionosphere. The average error of the
model turns out to be practically zero and RMSE is 0.166 MHz. For practical purposes,
as for calculating a radio path at a given radio distance, this error is within acceptable
limits. The established model allows predicting the values of the critical frequency of
the E-region, taking into account the influence of the short-time variations of the solar
activity, related to the rotational period of the Sun. The main application of this model is
to determine the lowest usable frequency when calculating a specific radio path over
Bulgaria.
conference
21st International Multidisciplinary Scientific GeoConference SGEM 2021
21st International Multidisciplinary Scientific GeoConference SGEM 2021, 16 - 22 August, 2021
Proceedings Paper
STEF92 Technology
SGEM International Multidisciplinary Scientific GeoConference
SWS Scholarly Society; Acad Sci Czech Republ; Latvian Acad Sci; Polish Acad Sci; Serbian Acad Sci & Arts; Natl Acad Sci Ukraine; Natl Acad Sci Armenia; Sci Council Japan; European Acad Sci, Arts & Letters; Acad Fine Arts Zagreb Croatia; Croatian Acad Sci
403-410
16 - 22 August, 2021
website
cdrom
7804
critical frequency; E-region; empirical model; solar activity; solar zenith
angle

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