Search

Abstract: To better and faster quantify the strength and impact of the ionospheric perturbations, we propose a new index for operational use in communication/navigation systems. Presented here is the analysis of selected events of strong disturbances observed with techniques based on Global Navigation Satellite Systems (GNSS) in order to show some insufficiencies when using existing geomagnetic indices. We found that the GNSS Total Electron Content (TEC) measurements and/or derivatives are outstanding candidates for defining a new ionospheric perturbation index, more specialised and therefore more effective. It is believed that the standardization and usage of the proposed perturbation index, together with other indices of similar nature, can prove helpful in reducing the space weather impact on the GNSS-based navigation and positioning. [Copyright &y& Elsevier]

Abstract: Ionospheric space weather effects can degrade the performance of global navigation satellite systems (GNSS), i.e. their accuracy, reliability and availability. However, well established ground based and innovative space based GNSS measurements offer the unique chance for a permanent monitoring of the electron density structure of the global ionosphere–plasmasphere system. In this paper we review various types of perturbations in the ionospheric plasma density and distribution. In order to analyze these space weather effects we use 30s sampled measurements provided by the global GPS ground tracking network of the IGS. Furthermore, to get a more comprehensive view on the perturbations analyzed also are simultaneously obtained GPS measurements onboard the LEO satellite CHAMP (challenging minisatellite payload). Whereas the ground based measurements show strong horizontal redistribution of plasma during ionospheric storms, the space-borne measurements indicate a severe vertical redistribution of the ionospheric plasma during the selected events. The role of the various dynamical forces such as meridional winds and electric fields is also discussed. [Copyright &y& Elsevier]