Performance comparison of differential GNSS, EGNOS and SDCM in different user scenarios in Finland

Positioning errors of stand-alone GNSS can be reduced with different real-time augmentation approaches. For many navigation and positioning applications, Satellite-Based Augmentation System (SBAS) and Differential code-based GNSS (DGNSS) can offer substantial improvement in the positioning accuracy. Finland is covered by EGNOS (European Geostationary Overlay Service) even though it is lying at the north-east margin of the coverage area. In addition to EGNOS, the neighboring SBAS system SDCM (System for Differential Corrections and Monitoring) has monitoring stations near Finland. In this work, the researchers at the Finnish Geospatial Research Institute (FGI) conducted some field experiments with mentioned SBASs and National Land Survey of Finland's (NLS) DGNSS service in order to find out reachable accuracies and rough estimates of availability in varying positioning conditions. Interest to SDCM grew due to its vicinity from Finland and also partly due to its ability to provide GLONASS corrections which EGNOS has not yet been able to offer.