## 4 Summary and Conclusions  
This contribution evaluates the performance of the coupled Galileo + GPS instantaneous medium-range positioning, with special attention paid to the application of the Galileo FOC satellites--E14 & E18--launched into incorrect elliptic orbital planes. Therefore, the main goal of the paper was to investigate the potential capability of these satellites in surveying and geodetic applications. In the paper we provided both a methodology of coupled instantaneous medium-range positioning and experimental performance analysis.  
In the first part of the study, we focused on the analysis of the signal power and noise of Galileo E14 & E18 satellites, comparing the results to other GPS and Galileo satellites. It was confirmed that the signal power of E14 & E18 satellites was basically higher than the signals of other Galileo satellites (up to 53 dB-Hz). This was clearly related to their lower orbital altitude over the area of the test stations. On the other hand, analysis of observational noise did not reveal any differences between all the European satellites. The inter-system comparison of the noise (GPS and Galileo) proved that the precision of code measurement of the latter was significantly better. The same effect, though less pronounced, was also observed in triple-frequency combination of phase observations.  
Further analysis was based on the positioning experiment and considered ambiguity resolution and coordinate domains as well as observable residuals. We confirmed the high performance of the instantaneous medium-range positioning based on the GPS-only constellation, providing unobstructed visibility of the satellites. When adding in Galileo observations, we did not see an important change in the performance of the ambiguity resolution. Both solutions, GPS and GPS + Galileo, provided competitive rates of ambiguity resolution success, reaching up to 99%. On the basis of the two scenarios, one with and one without E14 & E18 satellites, we found that the Galileo satellites launched into eccentric orbital planes did not deteriorate the ambiguity resolution process. On the other hand, we experienced significant worsening in the ambiguity domain when the Galileo-only constellation was applied. We believe that this was caused by the current uncompleted constellation and thus poor geometry of the Galileo satellites over the experimental area.  
Having analysed the precision of the solutions based on the coupled GPS + Galileo constellation, we can conclude that the E14 & E18 satellites do not have any negative impact on the coordinate domain. The differences between the standard deviation of fixed coordinates did not exceed 1 mm for plane components, whereas in the case of height this difference reached 6 mm.  
According to the obtained results, again we do not see any increased observation residuals corresponding to signals of E14 and E18. The standard deviation of the L1/E1 phase residualscorresponding to GPS, Galileo and E14 & E18 satellite signals were at a comparable level, in the range of 6.5-8.7 mm.  
Considering the above, precise positioning using Galileo satellites launched into incorrect orbital planes is feasible. Therefore, these satellites are applicable to most geodetic, surveying and many other solutions. This claim, however, holds true providing the precise ephemeris of the satellites.  
The work in this contribution was supported by the National Science Centre, Poland: project No. 2016/23/D/ST10/01546. The GNSS observational data from CORS network were kindly provided by VRSNet Ltd., Poland.  
[PERSON] designed and performed the experiments, analysed the data and discussed the conclusions. [PERSON] performed and analysed the experiment given in Section 2 and discussed the conclusions. [PERSON] supervised the investigations and discussed the conclusions.  
The authors declare no conflict of interest.