... Experimental base . ... The experimental base of the investigations is the topside sounding data obtained on board of the Intercosmos-19 and Cosmos-1809 satellites. ... It carried on board the following scientific payload: satellite ionospheric station for radio sounding of ionosphere (IS-338) and apparatus for the measurements of low-frequency electromagnetic field (VLF-2ME), electric component of high-frequency field (AHF-2K), electron temperature (KM-3), and spectrometer of photoelectrons (SF3-M)...