# Designation of the Quality of EGNOS+SDCM Satellite Positioning in the Approach to Landing Procedure
## 6 Conclusions  
The paper presents the results of research on the determination of the resultant quality of satellite positioning with use of SBAS supporting systems. It focuses in particular on presenting a modified weighted mean model used to determine the quality parameters of satellite positioning with use of measurement weights. The developed model defines the Multi-SBAS solution, because it combines single position solutions from the SBAS supporting system by means of using measurement weights. The authors proposed to apply measurement weights as a function of the inverse number of the tracked GPS satellites for which SBAS corrections were developed. The created model was adapted to two SBAS supporting systems, i.e., EGNOS and SDCM. The applied calculation strategy allowed for the determination of the resultant accuracy, continuity, availability, and integrity parameters of Multi-SBAS positioning in aviation. The developed mathematical model was verified during a test flight that was conducted in north-eastern Poland. The experiment was conducted on a Diamond DA 20-C aircraft, with a Sepentrio AsterRx2i geodetic receiver installed on board. The test results for the stages of approach to landing and the landing itself were elaborated. The conducted research demonstrated that:  
* The values of the standard deviations calculated in the proposed weighted mean model improved by 61-65% in comparison to the traditional arithmetic mean model;
* The resultant position error in 3D space calculated in the proposed weighted mean model improved by 1-7% in comparison to the traditional arithmetic mean model;The accuracy of determination of the vertical component h from the proposed weighted mean model improved by 1-14% compared to the standard arithmetic mean model;  
The resultant position error in 3D space calculated in the proposed weighted mean model improved by 1-37% in comparison to a single SBAS/EGNOS solution;  
The accuracy of determination of the vertical component h from the proposed weighted mean model improved by 1-73% compared to a single SBAS/EGNOS solution;  
The application of the Multi-SBAS positioning algorithm resulted in an increase in the nominal results of continuity and availability by 50% in comparison to the arithmetic mean model;  
The values of the integrity parameters (HPL, VPL) determined with use of the proposed weighted mean model improved by 62-63% in comparison to the standard arithmetic mean model.  
The SBAS positioning quality results obtained during the research demonstrated that the proposed computational strategy of applying the weighted mean model was valid and adequate to the set objective of the work. The developed resultant Multi-SBAS positioning system may prove to be highly effective and efficient in navigation calculations. In the future, further research is planned on the Multi-SBAS positioning model, also with use of other SBAS supporting systems [79].  
Conceptualization, K.K.; methodology, K.K.; software, K.K.; validation, K.K.; formal analysis, K.K.; investigation, K.K.; resources, A.C. and K.K.; data curation, A.C. and K.K.; writing--original draft preparation, K.K., D.W. and M.M.; writing--review and editing, K.K. and D.W.; visualization, K.K.; supervision, D.W., J.C., J.K.; project administration, D.W.; funding acquisition, K.K. All authors have read and agreed to the published version of the manuscript. This research was funded by Polish Air Force University in Deblin.  
Not applicable.  
The data presented in this study are available on request from the corresponding author.  
The authors declare no conflict of interest. The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript, or in the decision to publish the results.