Fig. 3From: Continuous Doppler sounding of the ionosphere during solar flaresSpectrograms recorded by the CDSS in the Czech Republic on 22 October 2014 from 13:45 to 14:55 at a 7.04 MHz, b 4.65 MHz, c 3.59 MHz, d Plasma frequency as a function of height obtained from ionospheric sounder (blue) and from IRI-16 model (red) at 14:00 UTBack to article page