Regional ionospheric TEC modelling; working towards mapping Africa's ionosphere

Currently the available data over the African continent does not allow for the construction of a truly representative ionospheric map for the purposes of long term predictions. In addition, the forecasting of the ionospheric variability over long term is a complicated task. This is because the ionospheric medium is continuously changing, it exhibits behavior that is not easily predictable and also requires a continuous and reliable database for comprehensive empirical models to be developed. However modelling ionospheric total electron content (TEC) changes over the short term is feasible especially during quiet conditions. In order to work towards generating ionospheric TEC maps to represent Africa's ionosphere, we have undertaken a feasibility study by using the South African Global Positioning System (GPS) receiver network to construct a regional model. This model generates TEC maps over the Southern African region at the minimum temporal resolution of 1 minute. The GPS TEC data as well as the modelled TEC are validated using ionosonde data. This paper will present an overview of regional GPS TEC modelling over Southern Africa and give a future direction towards continental TEC mapping.