The influence of the PPP-RTK reference station network configuration on position accuracy and real-time performance

PPP-RTK is a GNSS-based method for absolute positioning in real-time that has gained importance in recent years. Unlike network RTK, correction data can be provided as broadcast to an unlimited number of users. In Germany, a nationwide PPP-RTK service is about to be implemented. The service is being set up in cooperation with the surveying authorities of the federal states and the Bundesamt für Kartographie und Geodäsie (BKG). Two independent computing facilities at BKG and Zentrale Stelle SAPOS® guarantee a high level of reliability of the service. Although both facilities use the GNSS processing software GNSMART, the analysed reference station networks differ. The service is currently being tested with various scenarios and setups. Due to its redundancy, different configurations can be analysed in parallel.  The service performance is monitored in a nationwide monitoring network. Three of these monitoring stations are equipped with two identical receivers that are connected to the same antenna and can be used for detailed comparisons of the two service setups. We present results how the network configuration impacts the service performance with a special focus on the present ionosphere activity.