Experiments on the Ionospheric Models in GNSS

Abstract

In GNSS, one of the main error sources of the Standard Positioning Service (SPS) is introduced by the ionosphere. Although this error can be cancelled by combining two signals at different frequencies, most of the single - frequency mass - market receivers do not benefit from this cancel l ation. For that reason, a set of parameter s is included in the navigation message in order to compute the ionospheric delay of any observation by the Klobuchar model. The Klobuchar model is a very simple model that is able to remove more than the 50% of the ionospheric delay. Recently, more accurate ionospheric models have been introduced such as Global Ionospheric Map (GIM) or the F ast P recise P oint P ositioning ( F PPP ) ionospheric model. In previous works, with data gathered in Europe, it was shown the advantage of the F PPP’s ionospheric model. In this work, we conduct experiments to compare the performance of different ionospheric modelling methods including: Klobuchar, GIM s and F PPP. Our preliminary results show how F PPP and GIM s lead to better positioning precisions compared to the Klobuchar model. However, since data is not wide enough to cover different ionospheric cond itions, more experiments will be carried out in our future work to validate the current result s .