Assessment of GNSS multipath effects using open source software

The article evaluates the multipath effect in GNSS measurements using the RINGO software based on data from an automated geodetic monitoring system of one of the high-pressure hydroelectric power plants in the Russian Federation. The identified multipath values at the stations were assessed according to the criteria recommended by the International GNSS Service (IGS). The comparison results revealed that all reference stations of the automated geodetic monitoring system meet the IGS recommended criteria. Out of seven monitoring points, only one satisfies the multipath evaluation criteria, while two points exhibit unacceptable values. The possible cause of the low quality of satellite measurements at these stations could be obstacles near the stations that block the antenna’s radio horizon, interrupt, or reflect GNSS signals. It is recommended to include a preliminary analysis of GNSS measurements in the structure of the automated geodetic monitoring system. This analysis would help identify unsuitable locations for station placement in the deformation network and, if necessary, exclude the coordinates of monitoring points affected by significant multipath interference from further analysis. Additionally, it is recommended to conduct a preliminary analysis of GNSS measurements at differential geodetic stations to verify their compliance with IGS criteria. Based on this analysis, they could be integrated into the current structure of the State Geodetic Network.