Real-time GNSS positioning services — ROMPOS

Moving from GNSS position determination in post-processing to real-time position determination requires the development of complementary positioning systems at regional, national or local level. Complementary systems provide users with additional information (“differential corrections”) in order to be able to reach real-time positioning accuracy of decimetric or centimetre level. One such system including these services is ROMPOS (Romanian Position Determination System). The ROMPOS system was launched in Romania in September 2008. It is based on the national network of permanent GNSS stations which includes 58 stations (2009). The ROMPOS-RTK service provides the information needed to determine the position in real time with an accuracy of up to 2 cm with the help of specialised GNSS receivers. The ROMPOS-DGNSS service provides the information needed to determine the position in real time with an accuracy of up to 0.5 m, using specialised GNSS receivers. For access to services it is necessary for the user to have real-time access to the internet. The data is disseminated in two ways: single station data (differential corrections calculated on the basis of records from a single GNSS station) and “network” data (differential corrections resulting from a modelling on the area covered by the network of GNSS stations).