Ionospheric Radio Propagation

amplitude antenna approximately atmosphere attenuation auroral blackout collision component critical frequencies CRPL curves cycle D region decibels decrease dipole distance distribution disturbance diurnal variation E layer earth earth's magnetic field echoes effects electric electron density electron density profile ellipses equator extraordinary waves F₁ F₂ F2 layer factor fading foF2 Fresnel zone geographic geomagnetic Geophys given high latitudes incidence increases ionization ionogram ionosonde ionospheric absorption irregularities J. A. Ratcliffe kc/s magneto-ionic maximum frequency Mc/s measurements median medium meteor normal oblique observed obtained occur ordinary and extraordinary ordinary wave path loss phase velocity Phys plane polar cap predicted Proc pulse quency radiation radio propagation radio waves radius range ray path receiver refractive index region relatively shown in figure solar flare spread F sunspot number Terrest tion trail transmission transmitter vector vertical virtual height wavelength zenith angle