TY JOUR TI Inversion of backscatter ionograms into quasiparabolic ionospheric layer parameters KW ionosphere KW ionogram KW radio wave propagation KW backscatter ionospheric sounding JO Solar-Terrestrial Physics AU Ponomarchuk, S.N. AU Penzin, M.S. PY 2020 IS 6 PB INFRA-M Academic Publishing LLC.