On the performance of selected ionospheric modelling schemes in Precise Point Positioning

One of the most frequently investigated methods of position determination with GNSS is Precise Point Positioning — an absolute method which provides a solution with the accuracy close or even, under specific conditions, equal to relative mode. Initially the method took advantage of the ionosphere-free linear combination of dual-frequency GPS phase and code signals to overcome the negative impact of the ionospheric delay. However, recent progress led to the introduction of novel observational models based on uncombined signals. This paper investigates both of these commonly used models of PPP which importantly diverge from the methodology of ionospheric delay handling. The results have shown that the models may provide equivalent results, hence the common presumption that ionosphere-free linear combination provides noisier and slower converging solution is not justified.