Monitoring of networked RTK reference stations for coordinate reference system realization and maintenance – case study of the Czech Republic

Abstract Networked Real-Time Kinematic (NRTK) is the most widely used GNSS (Global Navigation Satellite Systems) positioning technique in surveying practice due to its speed, operability and sufficient accuracy. Positioning using NRTK methods in the European Terrestrial Reference System ETRS89 obligatory coordinate system is tied to the positioning of reference stations of the RTK network. Monitoring of GNSS reference stations provides both the determination of the position of individual stations in the obligatory coordinate system and the monitoring of daily position deviations of individual stations. The application to four networks of GNSS reference stations in the Czech Republic has demonstrated the accuracy of the positioning of stations from the daily solution at the level of 1.2 mm in the horizontal components and 3.8 mm in the vertical component. This accuracy is quite suitable for NRTK methods that determine position with centimetre accuracy. At the same time, it allows to detect the behaviour of time series of coordinates of individual stations – sudden jumps, linear and periodic trends. The accuracy achieved also allows tracking geokinematic movements.