have crosschecked two ionospheric models, the International Reference Ionosphere Extended to the Plasmasphere (IRI-Plas 2017; <http://www.ionolab.org/>; @Sezen2018) and the International Reference Ionosphere (IRI 2016; <https://ccmc.gsfc.nasa.gov/>). We applied the global instantaneous ionospheric maps of hmF2 in area covered by dTEC maps. The hmF2 magnitude over a large area containing the IPP tracks (see below) fluctuates only slightly around the value at the altitude of 250 km during our observations.

Results {#Sect:Results}
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Figure \[Figure2\](a-h) shows a collection of the eight solar dynamic spectra on 2014 January 8. The antennas are scattered in Europe. The map of their locations is displayed in panel (i) of the figure. All instruments operated in overlapping frequency bands. In the spectrograms SCs can be recognized by their distinctive spectral shapes. Most SCs belong to the prevalent inverted V-like type. Some SCs appear in form of lanes, corresponding to the fiber-like type. A few SCs cannot be classified with the classification scheme defined by @Koval2017.

In Figure \[Figure2\](i) we plotted the IPP trajectories for every Sun-antenna pair using equation \[Eq1\]. The coordinates of antennas are known. The solar zenith and azimuth angles were extracted with the high-precision solar position algorithm [@Reda2004]. The lengths of IPP tracks depend 