## 5 Conclusions  
The statistical analysis of the GNSS time series holds paramount importance in the field of Space Geodesy, serving as a cornerstone for extracting meaningful information from the vast and intricate datasets generated by Global Navigation Satellite Systems. The utilization of statistical methods in the analysis of GNSS time series is multifaceted, addressing various challenges inherent in the measurements and providing valuable insights into the Earth's dynamic processes.  
This paper presents the main ideas of the non-classical measurement theory and a software solution for their practical implementation in the field of the metrological diagnostics of long-time series obtained at permanent GNSS stations for different levels. To analyze the presence of residual unaccounted-for systematic errors at a particular GNSS station, we propose a new software package called PS-NETM (Python software--Non-classical Error Theory of Measurements). Its main functionalities are summarized, and a numerical example is given to demonstrate the software's capabilities in terms of diagnosing the probabilistic form of measurement distributions, which is based on the use of confidence intervals for estimating the skewness and kurtosis of large samples, followed by the application of [PERSON]'s \(\chi 2\) test.  
Based on this example, it can be argued that the distribution of errors for the selected time series of permanent GNSS stations in Europe is not perfect and does not follow the law of normal distribution.  
The results of this work reveal a large problem with the current GNSS time series, which is unaccounted-for small systematic errors. We feel it is vital to make such an analysis before conducting any experiments on a particular GNSS station. The research shows that the C1 station HELG, which is considered very reliable by EPN, has some data pathology. In other words, some large systematic errors are present there. These might include multipath effects, unreliable antenna placement, the movement of underground waters, which disturb the antenna, etc. The sources of such errors should be investigated individually at each station.  
Conceptualization, S.S. and P.D.; methodology, P.D. and D.M.; software, V.K.; validation, S.S., D.M. and P.D.; writing--original draft preparation, S.S. and A.M.; visualization, V.K. and A.M.; supervision, S.S. and P.D. All authors have read and agreed to the published version of the manuscript.  
This research received no external funding.  
The software PS-NETM is available on GitHub platform at [[https://github.com/[PERSON]/PS-NETM/](https://github.com/[PERSON]/PS-NETM/)]([https://github.com/[PERSON]/PS-NETM/](https://github.com/[PERSON]/PS-NETM/)) (accessed on 15 February 2024).  
The authors want to thank [PERSON]--Ukrainian scientist, astronomer, mathematician. His scientific works are devoted mainly to different aspects of the non-classical theory of errors development, studying its axiomatic foundations and the creation of the adapted  
Figure A4: HELG station histogram of coordinate distribution.  
Figure A5: PTBB station time series graph.  
Figure A6: PTBB station histogram of coordinate distribution.