Z-wave Occurrence and Propagation Patterns in Topside Sounding of the Earth Ionosphere

This work analyzes the occurrence probability of the Z-component trace on topside-sounding ionograms in the experiments aboard the Interkosmos-19 satellite and the space station Mir. The orbit height of Mir was around 350 km, while the perigee and the apogee of Interkosmos-19 were at 500 km and 950 km from the Earth surface.