Investigating Space Plasma Dynamics over Namibia Using Signals from Global Navigation Satellite Systems like GPS.
Earth’s Ionosphere extends from 50 to 1 200 km above its surface and comprises an electrically-conducting space plasma composed of negatively charged electrons and positively charged ions of varying density. Ionisation results from the upper neutral atmosphere’s dissociation by hard X-ray and Extreme Ultraviolet (EUV) solar radiation .
The ionosphere is a dispersive medium, affecting all radio signals propagating through it by delaying the group and advancing the phase with a time increment proportional to the ionospheric Total Electron Content (TEC) and inversely proportional to the square of the carrier frequency. Lower frequency signals are refracted more than higher frequency signals, leading to a slightly longer refracted path length through the ionosphere.