# Characterization of Carrier Phase-Based Positioning in Real-World Jamming Conditions
## 4 Analysis and Results
### Analysis 6: The Network Solution
These dents appear as a result of satellites at TA10 loosing fix at the beginning of the jamming incident, and being reintroduced in the solution near the end of the jamming incident (which ends at 18:18, but a few satellites already reappear at 18:07). \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Monitor Station Solution** & **East std. [m]** & **North std. [m]** & **Up std. [m]** \\ \hline _Baseline standard deviation_ & 0.006 & 0.013 & 0.006 \\ \hline \hline \end{tabular}
\end{table} 
Table 10: Monitor station standard deviation during the jamming incident in Case 1. Figure 17: Number of satellites in the monitor station solution during the period 11:00–13:00 GPS time of the Case 1 incident. In other words, the jamming incident is registered by the network, but does not seem to impact the performance of the network besides the affected station itself--just like what was seen in Case 1. While for this paper, a VRS solution was used for NRTK positioning, there are different methods for network processing that were not investigated. A Flachen korrektur parameter (FKP) [39] relies heavily on (typically linear) interpolation of observations from the three nearest reference stations, in combination with the original observations from the nearest of them. Therefore, such a solution may be more vulnerable to jamming in any of these three stations, while completely unaffected by the remaining network. Several other NRTK methods exist, such as pseudo-reference station (PRS) and master auxiliary concept (MAC). A good description of the relationship between these methods is provided by [40]. Moreover, for future work, the more recently introduced PPP-RTK (also referred to as SSR or PPP-AR) [41; 42] method would also be interesting to evaluate. This also highlights that there are still a lot of scenarios to be investigated with regards to jamming on NRTK. Apart from the processing method, investigations into the impact of network density and the position of the jammed reference station relative to the rover are also important in evaluating the robustness of NRTK. It has been shown that using dense networks has benefits to accuracy [43], and it is very possible that dense networks would also be more robust to the jamming of a single station. _Summary: The TAPAS network solution is unaffected by the jamming incidents, except for the station being jammed. No impact is seen on the rover positioning performance during the incidents._  
_It should, however, be noted that this concludes nothing about network RTK in general. The impact of the processing method has not been investigated. It is also very possible that a sparse network would be more affected due to longer baselines between reference stations. Furthermore, in a sparse network it is possible that there will be larger consequences for rover positioning, if especially the nearest reference station is affected by jamming._  
Figure 18: Fixing rate of the TAPAS network during the incident in Case 2. This shows the percentage of available satellites that are integer fixed in the network.