# Sampling Rate Impact on Precise Point Positioning with a Low-Cost GNSS Receiver
## 3 Results
In this sense, if the low-cost GNSS receiver was set up to 0.1 s, the obtained values of the standard deviation should be smaller than the geodetic receiver, this was not found. The difference obtained at 0.1 s by the low-cost GNSS receiver is higher compared to the one obtained with geodetic receiver when constant in horizontal and vertical components (Figures 8 and 9). Table 2 presents a summary of the values obtained for the PPP-static mode. For the geodetic receiver, the obtained results are similar in all cases with a precise obtained solution. The low-cost GNSS receiver presented solutions in cm order, nevertheless, at 1 and 15 s the obtained solutions are similar to the solutions from the geodetic receiver. For the kinematic mode, a positive relationship between the observation recording rate and the standard deviation was found (Figure 10). That is, the higher the observation recording rate, the higher the standard deviation values. However, for the difference  
Figure 8: Difference between estimated and precise position of low-cost and geodetic receivers at 0.1 and 0.2 s respectively, by processing with PPP-static mode. Figure 7: Standard deviation (95%) of estimated positions of low-cost and geodetic receivers by processing with PPP-static mode. between the estimates and precise coordinates, the differences obtained are similar and greater than the obtained values from the geodetic receiver. In all cases for the height of the low-cost GNSS receiver the values obtained are higher and are more suitable at 1 s (Figure 11)  
Nonetheless, when the low-cost GNSS receiver was set up to 0.1 s, the results of the difference between the estimated and precise positions (Figure 12) and the standard deviation (Figure 13) are greater than the geodetic receiver. The obtained differences of the precise coordinates and estimated coordinates for the low-cost GNSS receiver are higher than the geodetic receiver in all cases (Table 3). In comparison to the static mode, where the behavior of the difference of 1 s is similar to the geodetic receiver, this is not found. In all cases the standard deviation of the low-cost GNSS is greater than the geodetic receiver. \begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline \multirow{2}{*}{**Receiver**} & **Sampling** & **DLAT** & **DLON** & **DHGT** & **SDLAT** & **SDLON** & **SDHGT** \\  & **Rate (s)** & **(m)** & **(m)** & **(m)** & **(m)** & **(m)** & **(m)** \\ \hline \multirow{8}{*}{Low-cost} & 0.1 & 0.045 & \(-0.116\) & \(-0.179\) & 0.155 & 0.390 & 0.410 \\  & 0.2 & 0.057 & \(-0.122\) & \(-0.127\) & 0.069 & 0.108 & 0.340 \\  & 1 & 0.007 & \(-0.135\) & \(-0.112\) & 0.035 & 0.050 & 0.236 \\ \cline{1-1} \cline{2-7} GNSS & 5 & 0.042 & \(-0.014\) & \(-0.236\) & 0.142 & 0.364 & 0.270 \\  & 15 & 0.001 & \(-0.169\) & \(-0.159\) & 0.048 & 0.037 & 0.152 \\  & 30 & \(-0.039\) & \(-0.169\) & \(-0.15\) & 0.197 & 0.470 & 0.368 \\ \hline \multirow{8}{*}{Geodetic} & 0.2 & \(-0.007\) & \(-0.007\) & 0.037 & 0.004 & 0.005 & 0.018 \\  & 1 & \(-0.007\) & \(-0.006\) & 0.038 & 0.004 & 0.005 & 0.018 \\ \cline{1-1} \cline{2-7}  & 5 & \(-0.007\) & \(-0.007\) & 0.038 & 0.004 & 0.005 & 0.018 \\ \cline{1-1} \cline{2-7}  & 15 & \(-0.007\) & \(-0.007\) & 0.04 & 0.004 & 0.005 & 0.017 \\ \cline{1-1}  & 30 & \(-0.007\) & \(-0.007\) & 0.041 & 0.005 & 0.006 & 0.022 \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Differences and Standard deviation obtained at different sampling rates for the PPP-static mode. Figure 9: Standard deviation (95%) of estimated positions by processing with PPP-static mode: (**a**) low-cost receiver at 0.1 s; (**b**) geodetic receiver at 0.2 s.  
Figure 11: Difference between estimated and precise positions of low-cost and geodetic receivers by processing with PPP-kinematic mode. Figure 12: Difference between estimated and precise positions of low-cost and geodetic receivers at 0.1 and 0.2 s respectively, by processing with PPP-kinematic mode. Figure 10: Standard deviation (95%) of estimated positions of low-cost and geodetic receivers by processing with PPP-kinematic mode.