## 3 Results  
The setup for the field test based on the proposed A-VTTCES-KF is unchanged with the one for the stationary tests using the WNLS as illustrated in Figure 2. Furthermore, the corresponding parameter definitions for the GNSS SDR in the experiment are listed in Table 4.  
Figure 9: GNSS SDR architecture using the proposed A-VTTCES-KF algorithm. LR is the loop rate of the update. Both the carrier-phase-based real-time kinematic (RTK) positioning solutions and pseudo-range-based differential global positioning system (DGPS) solutions will be produced using the open-source package program, RTKLIB [77]. The related parameter settings for the RTK positioning algorithms are provided in Table 5. Moreover, a short baseline which is far less than 20 kilometers is used in the field tests. As shown in Figure 10, the trajectory is illustrated, and it is provided by the reference receiver of Trimble R10 in our work. Figure 11 demonstrates the view of the sky plot for all the contributed GPS SVs in the experiment and eight satellites are included. \begin{table}
\begin{tabular}{l l} \hline \hline
**Parameters** & **Values** \\ \hline System and frequency & GPS L1 C/A \\ IF sampling rate & 10.125 MHz \\ Coherent integration time & 5 ms \\ VT LR & 5/10/20 Hz \\ ST LR & 200 Hz \\ Bandwidth of 3 rd-order PLL for ST & 18 Hz \\ Bandwidth of 3 rd-order PLL for VT & 5 Hz \\ Discriminator for code phase error & Noncoherent-early-minus-late-power discriminator \\ Discriminator for carrier phase error & Costas two-quadrant arctangent discriminator \\ Early-late spacing of code discriminator & 0.2 chips \\ Re-acquisition algorithm & Not used \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Parameter settings of the GNSS SDR for the combined kinematic and static field test. Figure 10: Trajectory of the field test in terms of Situation #3 produced by the Trimble R10 Receiver. \begin{table}
\begin{tabular}{l l l} \hline \hline
**Parameters** & **Values** & **Descriptions** \\ \hline Positioning mode & Kinematic & Carrier-phase-based kinematic positioning \\ Integer ambiguity resolution & Continuous & Continuously static integer ambiguities are estimated and resolved \\ Min ratio to fix ambiguity & 1.5 & Set the integer ambiguity validation threshold for the ratio test; the test is related to the ratio of squared residuals of the best \\ System and frequency & GPS L1 C/A & Single frequency positioning \\ Ionosphere correction & Broadcast & Apply broadcast ionospheric model \\ Troposphere correction & Saastamoinen & Apply Saastamoinen model \\ Satellite Ephemeris/Clock & Broadcast & Use broadcast ephemeris \\ Elevation mask & 10 degrees & Set elevation mask angle in degree \\ Estimator mode & Post-processing & Forward filter solution \\ \hline \hline \end{tabular}
\end{table} 
Table 5: Parameter settings for RTK positioning using the open-source package program of RTKLIB [77]. The trends of the signal power for all the tracking channels within the testing duration are provided in Figure 12 where U-Blox represents the estimations produced by the low-cost commercial U-Blox receiver. The SV10, SV20 maintain stable \(C/N_{0}\) levels during the test due to the fact that they are embraced with the very high elevation angles. As to the other SVs from which the incoming GNSS signals are sometimes accidentally masked by the obstructions, e.g., the foliage and buildings during the whole testing. Furthermore, the received signals related to SV8, SV24, and SV32 are more frequently reduced by the environmental interference and blockage when compared with other signals, but the signal power can still be close to the level of the commercial U-Blox receiver in which the re-acquisition algorithm must be applied to confirm a high competition ability in the fierce commercial markets. It implies that the tracking performance of the GNSS receiver can highly be improved with the VT technique. Figure 11: Sky plot of the SVs for the field test for Situation #3.