# GNSS Positioning Using Mobile Devices with the Android Operating System
## 4 Results and Discussion
### Comparison between U-Blox and Smartphones Results  
Another dedicated test was performed for comparing the results obtained with the smartphones and those with the other low-cost receiver (u-blox). All receivers were settled only on the site with the best satellite visibility (site B), close to each other, to verify the performances in the best possible conditions (good satellite visibility, no obstacles, or electromagnetic disturbances). The authors performed two different measurement campaigns with a session length of 10 mins and 30 mins, respectively. In the first case (Table 6), it seems that the smartphones' performances were better than those obtainable with the u-blox receiver. This is really a strange behavior and was not confirmed if the longer session is analyzed (Table 7). This strange result is probably due to the noise of the raw GNSS measurements collected by the smartphone. Generally, it is really difficult to filter and de-noise these observations. \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Method** & **Time** & **East** & **North** & **Up** \\ \hline Static & _10 min site A_ & 8.991 & 10.462 & 10.933 \\ SPP & _10 min site A_ & 27.983 & 20.626 & 42.507 \\ \hline Static & _10 min site B_ & 0.048 & 0.142 & 0.118 \\ SPP & _10 min site A_ & 6.418 & 5.791 & 11.126 \\ \hline Static & _30 min site A_ & 3.915 & 6.844 & 10.131 \\ SPP & _30 min site A_ & 33.267 & 24.791 & 71.716 \\ \hline Static & _30 min site B_ & 0.864 & 0.736 & 1.817 \\ SSP & _15.932_ & 12.784 & 19.766 \\ \hline Static & _35.827_ & 16.135 & 21.665 \\ SPP & _60 min site A_ & 58.724 & 39.226 & 88.549 \\ \hline Static & _60 min site B_ & 0.959 & 0.445 & 2.071 \\ SPP & _50.047_ & 35.247 & 39.707 \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Huawei P10+. Results obtained with RTKLIB software, considering different session lengths and locations. Values in meters. \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Method** & **Time** & **East** & **North** & **Up** \\ \hline Static & _10 min site A_ & 1.246 & 0.955 & 1.346 \\ SPP & _10 min site B_ & 0.782 & 0.668 & 0.527 \\ \hline Static & _10 min site B_ & 0.024 & 0.016 & 0.034 \\ SPP & _10 min site A_ & 0.492 & 0.321 & 0.593 \\ \hline Static & _30 min site A_ & 34.991 & 33.448 & 81.132 \\ SPP & _30 min site A_ & 3.071 & 1.222 & 2.81 \\ \hline Static & _30 min site B_ & 0.058 & 0.013 & 0.044 \\ SSP & _0.908_ & 0.443 & 0.794 \\ \hline Static & _156.024_ & 303.553 & 287.713 \\ SPP & _60 min site A_ & 5.425 & 2.696 & 4.748 \\ \hline Static & _1.246_ & 0.955 & 1.346 \\ SPP & _0.782_ & 0.668 & 0.527 \\ \hline \hline \end{tabular}
\end{table} 
Table 5: Huawei P10+. Results obtained with LGO software, considering different session lengths and locations. Values in meters. According to the Table 5, the results are more accurate than precise for smartphone while u-blox provides better results both for accuracy and precision during the same time interval. For the session length equal to 30 minutes (Table 9) the smartphone results are slightly worse than in the previous case because the session length is half of that (Table 8).