Single-Epoch Decimeter-Level Precise Point Positioning with a Galileo Five-Frequency Ionosphere-Reduced Combination

Currently, there are two main methods for single-epoch decimeter-level precise point positioning (PPP); one is a model based on ambiguity-fixed ionosphere-free (AFIF) observations, and the other uncombined (UC) PPP. The implementation of these models requires both extra-wide-lane (EWL) wide-lane (WL) ambiguity fixing. Different from existing methods, this paper proposes multi-frequency ionosphere-reduced (IR) PPP suitable positioning. Based Galileo five-frequency data, optimal selection strategy IR combinations first studied with ionosphere, noise level wavelength factors considered. Then, selected combination, models, namely IR(EST) IR(IGN), established according to whether ionosphere parameters estimated or ignored. Finally, proposed verified real tracked data globally distributed stations, further compared AFIF/UC in terms performance time consumption. relationship between equivalent ranging error satellite elevation analyzed. lower is, larger residual its impact weakened by downweighting observations adjusting cut-off during partial fixing (PAF) process. results show that basically same, can achieve horizontal vertical accuracies better than 20 cm 40 cm, respectively. Compared similar accuracy only step EWL fixing, at same time, have varying degrees improvement consumption: 38% shorter AFIF 97% UC model.