T h e pap er pr es ents t h e r esults of an analysis of t h e corr espond enc e b etw e en mod el r epr es entations t h e mont hly m ean diurnal d ep end enc es of critical fr equ ency and v ertical

The article analyzes the errors in estimating the parameters of the main ionospheric maximum, plasma frequency foF2 and its height hmF2, by automated systems for processing the vertical radio sounding data of the ionosphere at the IZMIRAN station in 2018, during a period of low solar activity. It considers the results of the two most commonly used programs that scale observatory registrations of the ionosphere state, ARTIST 5, part of the DPS-4 ionosonde (DPS–ARTIST complex), and Autoscala 5.1, adapted for the Parus-A ionosonde (Parus–Autoscala complex). An independent system for analyzing ionograms from the Parus-A ionosonde by an operator is used as an etalon in comparing the results. It is shown that the foF2 estimates by both automated systems are sufficiently reliable with a standard deviation of 0.1 MHz. The errors in hmF2 estimation differ significantly and are characterized by a general negative bias, depending on the year’s season, and are most significantly expressed in the local noontime. The statistical values of the hmF2 deviations, in the common case, are significantly larger for the DPS–ARTIST system and are principally close to the results of the comparison with the Millstone Hill incoherent scatter radar data.

This paper considers the possibility of the deep trough formation in the integral amplitude–frequency dependence of the wave field at the classical limiting paths of a single-hop ionospheric radio waves propagation under conditions of low solar activity. Calculations based on the global ionospheric model with both standard (IRI) and alternative dynamic (IRI + GDMF2) representations of the F2 layer of the ionosphere are compared with the experimental results of multifrequency oblique ionospheric sounding (OIS). It is shown that it is fundamentally possible to use the model to describe this feature based on the energy parameters of the radiation transfer problem in the ionosphere.

A possibility of estimating the local value of the plasma frequency of the F2 layer ionospheric maximum (subionospheric region) according to the multifrequency sounding data of the arctic ionosphere...

The Doppler spectrum of an exact time harmonic radio signal for the frequency of 5 MHz on the Moscow–Akademik Vernadskii Ukrainian Antarctic station radio path in November 2002, which had two clearly...