Space Weather Monitoring by Ground and Space based GNSS techniques

Kurzfassung

Since the availability of GPS signals in the early nineties, ionosphere sounding techniques using Global Navigation Satellite Systems (GNSS) such as GPS and GALILEO are well established. Due to the dispersive nature of the ionospheric plasma, dual frequency signals can effectively be used to derive the integral of the electron density along the ray path called Total Electron Content (TEC). Thus, dense networks of ground receivers allow constructing regional and global TEC maps which may effectively be used to study the solar control of ionospheric processes. Furthermore, GNSS receivers installed on Low Earth Orbit (LEO) satellites may be used to derive vertical electron density profiles from the satellite orbit height downward by radio occultation measurements. The space based navigation signals received by the zenith viewing antenna onboard a LEO satellite provide a unique data set to reconstruct the topside ionosphere/plasmasphere electron density distribution. The talk reviews specific observations obtained in DLR Neustrelitz by ground based GPS measurements in Europe and at both polar regions. Reported are results obtained from space based radio occultation measurements in the limb sounding mode and navigation measurements onboard the German geo research satellite CHJAMP.