[G06-4] Ionosphere and space weather II

[G06-4-05] Assessment and comparisons of ionospheric vertical total electron content products

^○Michael Schmidt¹, Alberto Garcia-Rigo², Eren Erdogan¹, Andreas Goss¹, David Roma-Dollase³, Manuel Hernandez-Pajares² (1.Technical University of Munich (DGFI-TUM), Munich, Germany, 2.Technical University of Catalonia (UPC-IonSAT), Barcelona, Spain, 3.University of Barcelona (Department of Engineering), Barcelona, Spain)

Accurate modelling of the ionosphere is crucial for GNSS-based applications in positioning and navigation to mitigate the effect of ionospheric disturbances. Large volumes of GNSS data, which are acquired from continuously operating terrestrial GNSS receivers and distributed worldwide, pave the way of monitoring the Vertical Total Electron Content (VTEC) of the ionosphere with an increasing accuracy as time goes by. In this context, many analysis centres are v providing VTEC products with different latencies (e.g. real-time, hourly, daily) and quality as well as they spent effort to improve their models.

The UPC-IonSAT group generates global VTECs maps both in real-time and in post-processing mode using its Tomographic Model of the Ionosphere electron content (TOMION) software. This software works as an assimilative model of GPS data to create a global 2-layer voxel tomographic representation solved with a Kalman filter.

The VTEC model of DGFI-TUM is based on tensor products of trigonometric B-spline functions in longitude and polynomial B-spline functions in latitude for a global representation. The unknown parameters of the model are sequentially estimated by assimilating GNSS observations using a Kalman filter.

In this study, the performance of the VTEC maps, particularly derived from UPC and DGFI-TUM, is assessed, using e.g. the differenced STEC analysis method and Jason-2 altimetry comparisons. We also compare our results with other available products, e.g. IGS VTEC maps. Furthermore recent model improvements are presented.