## 4 Results and Analysis  
The positioning errors for the proposed PPP solutions are given in Figure 6. It is shown that the real-time processing scenario can be converged to meter-level for Galileo-only observations or sub-40 cm-level for GPS-only and the combined GPS/Galileo observations in horizontal directions after approximately 30 min. As observation time increased, the horizontal position accuracy for the Galileo-only PPP solution improved to sub-meter levels, reaching sub-50 cm after approximately 1.5 h, while the GPS-only and the combined GPS/Galileo PPP solutions achieved positioning accuracy less than 30 cm. For the vertical components, the processing results demonstrate positioning accuracy within 1 m after 30 min for Galileo-only PPP solution and within 40 cm after 30 min for GPS-only and the combined GPS/Galileo PPP solutions. For the post-processing solutions, both the horizontal and the vertical positioning errors after 30 min are within 50 cm for the Galileo-only PPP solution and less than 30 cm levels using GPS-only and the combined GPS/Galileo PPP processing scenarios. To further study the Xiaomi 11T GNSS positioning performance, the positioning errors for horizontal and vertical components after 30 min, 60 min, and 120 min were computed for each IF-PPP solution as illustrated in Figure 7.  
By the 30 min mark of observation, the GPS-only IF-PPP solution achieved horizontal positioning accuracies better than 35 cm and 20 cm when using real-time and final correction products, respectively. By the 60 min mark, all horizontal positioning errors using the GPS-only IF-PPP solution were within 29 cm. Furthermore, by the 120 min mark, horizontal positioning accuracy improved to better than 20 cm when using CNES products and 28 cm with final IGS products. The vertical positioning accuracies of the GPS-only IF-PPP solution at 30 min of observation were approximately better than 47 cm and 53 cm when using real-time and final correction products, respectively. By the 60 min and 120 min marks, the vertical accuracies improved to better than 30 cm for all correction products. The Galileo-only IF-PPP solution achieved horizontal positioning accuracies better than 25 cm using real-time CNES products by the 30 min mark and better than 45 cm using final IGS products by the 60 min mark. By the 120 min mark, horizontal accuracies improved to better than 25 cm with real-time products and 15 cm with final products. Regarding the vertical directions, the Galileo-only IF-PPP solution achieved accuracy better than 35 cm across all analyzed time marks and correction products. The final IGS products demonstrated a superior performance at the 30 and 60 min marks, with vertical accuracies better than 10 cm. Figure 6: The horizontal (**Left**) and the vertical (**Right**) errors using GPS, Galileo, and the combined GPS/Galileo observations on DOY 71. The combined GPS/Galileo IF-PPP solution demonstrated a horizontal accuracy of approximately better than 30 cm across all analyzed time marks and products. However, it can be noticed that CNES products achieved better than 20 cm by 30 min time marks. Regarding the vertical accuracy using the combined GPS/Galileo IF-PPP solution, approximately 30 cm accuracy was achieved using CNES across all analyzed time marks, while better than 25 cm was achieved using final IGS products across all analyzed time marks. Similarly to the Galileo-only solution, the combined GPS/Galileo IF-PPP solution vertical accuracy was better than 15 cm for 30 and 60 min time marks using final products. An analysis of the positioning error accuracy across different time windows indicates that the positioning performance remains generally stable, with minor fluctuations in accuracy over time. Notably, real-time CNES products and single-constellation solutions occasionally demonstrated slightly improved performance at certain time intervals.