## 3 Precise Positioning Using Uncombined PPP (UPPP) Algorithm
### UPPP Positioning Accuracy Analysis  
In this subsection, we provide the results of a kinematic test carried out by the same dual-frequency Xiaomi Mi8 device as the static experiment. A kinematic test was carried out on 22 April 2022 with a duration of almost one hour in mostly open-sky environment with overpasses, Calgary, Alberta, Canada. Figure 11 shows the kinematic test configuration and the reference vehicle's path in this experiment. The kinematic experiment involved three geodetic receivers (two U-blox F9P and one Septentrio AsteRx-m2), as shown by the three pick arrows in Figure 11, and six smartphones for our future research (here we only used the Xiaomi Mi8 Black dataset). The phones were placed on the vehicle roof. The offsets between all units were measured and applied prior to comparison. The reference trajectory of the vehicle during the kinematic experiment was obtained by the RTK fixed solutions from the three geodetic receivers as the rover  
Figure 11: Kinematic experiment done on 22 April 2022 (a): test configuration and (b): Reference trajectory). Figure 10: C/N0 records of GPS PRNs with problem in carrier-phase observations logs for Xiaomi Mi8 and Samsung S20 (Blue dots: epochs of carrier-phase observations with no change over time). receivers. A geodetic receiver on a geodetic pillar (with true position) on the rooftop of the Civil Engineering building, University of Calgary, was also selected as the base receiver. Table 5 provides GNSS data information and processing setting. Figure 12 provides the positioning errors for Xiaomi Mi8 using the two RINEX files (RINEX by GEO++ RINEX logger and our converted RINEX) in the post-processed mode. The results of the RINEX file from the GnssLogger App were not provided since the obtained accuracy was at the single point positioning (SPP) accuracy level due to the frequent cycle slip detected. It should be noted that the root mean square (RMS) values provided in this figure have been computed using all epochs. In this figure, the cumulative distribution error (CDE) plots for the horizontal positioning error are also provided. The results confirmed the better performance of the converted RINEX in terms of East, North and Up RMS values and the 50 th percentile error. There are many studies devoted to the PPP smartphone positioning, among them we may refer to at least two, [7; 43]. In Ref. [7], the Geo++ RINEX logger was used; while in the second study, the authors employed their own developed conversion tool in order to generate the RINEX file [43]. [PERSON] et al. [7] employed the dual-frequency GPS (L1/L5) and Galileo (E1/E5a) observations from a Xiaomi Mi8 smartphone obtained from the Geo++ RINEX logger. Their numerical results showed that the positioning performance of the PPP algorithm employing the ionosphere-free combination was at the meter-level, in kinematic mode. Our positioning accuracy was better than their work, which might be due to differences in measurement environment and employed mathematical model, as well as considering GLONASS observations in our contribution. [PERSON] et al. [43] also proposed a modified single-frequency PPP algorithm in which separate clock biases for pseudorange and carrier-phase observations are estimated. Using a Xiaomi Mi8 smartphone, the average horizontal and vertical RMS error were 0.81 m and 1.65 m, respectively. The difference in accuracy is acceptable since they used the single-frequency data and the predicted ICS products.