Potential of an Ionospheric Disturbance Index to Estimate the Ionospheric Impact on GNSS

Abstract

Ionospheric perturbations can have a strong influence on the use of global navigation satellite systems (GNSS) and other space-based systems. The detection and estimation of spatial and temporal variations of electron density in near real-time is challenging and subject to current research. Based on former studies on the Disturbance Ionosphere Index (DIX) [1], here we present preliminary results concerning its capability to deduce also directional information on horizontal structures of the ionospheric electron content. Related results are derived from GNSS data sets obtained over Europe during a moderate ionospheric storm in October 2011. Although being limited due to the uneven data coverage over Europe, the derived index indicates the potential of providing valuable information on the actual performance of GNSS applications. The index is designed to be reliable and robust and allows an easy and objective interpretation. The calculation of the ionospheric disturbance index is based on the Total Electron Content (TEC) which has been confirmed in many publications to be an outstanding parameter for quantifying the range error and the strength of ionospheric perturbations. The quality of the index is dependent on the density of the used GNSS data base. The shown analysis results are calculated using the IGS and EUREF GNSS reference networks. DIX shall be made available to registered users in near real-time via the Ionospheric Monitoring and Prediction Center (IMPC) just established at DLR (http://impc.dlr.de).