Geodetski zavod Celje d.o.o. (GZC) is an international company with more than 60 years of experience providing consultation and technical assistance services to the public sector. GZC is specialised in spatial and rural development planning, implementation, monitoring and evaluation as well as in the provision of technical assistance in the above fields for capacity building of national and local institutions, managing numerous projects mainly in Slovenia and the Western Balkans. In particular, GZC is the contractor of the Slovenian Agency for Agricultural Markets and Rural Development for all Common Agricultural Policy (CAP) controls, both with remote sensing and on the spot checks (OTSC), since 2006.
For the implementation of CAP controls, the eligible agricultural area, i.e. where actual crops are grown, needs to be identified. For this purpose, the performance of OTSC with GNSS devices is usually required, e.g. if no suitable satellite imagery of a specific area is available. In this sense, as soon as the EGNOS Open Service was declared available in 2009, GZC confirmed its validity for CAP OTSC, following the Joint Research Centre’s validation protocol based on the ISO 5275 norm, and has, as a result, used it for this type of in-field campaigns since then. As EGNOS is integrated in almost all professional GNSS devices, GZC has been able to use it with different equipment along the years, namely Hemisphere A100, Hemisphere A325, SXBlue II+ GNSS, Trimble GeoXT, Trimble 6000 series, Trimble Juno and Leica Zeno 20.
In the specific case of Slovenia, there is a network of permanent GNSS base stations that provides DGNSS and RTK corrections. However, mobile networks, which are needed to receive this data, present a limited coverage in remote rural areas. This drawback is overcome by EGNOS, as its signal is broadcasted by geostationary satellites, so it is constantly available almost anywhere in Europe (rural and urban visibility maps can be consulted in the EGNOS User Support Website). In addition, EGNOS is free of charge, providing significant economic savings to GZC, as they require corrections for about one hundred GNSS units. For these reasons, GZC relies on the EGNOS Open Service as the standard GNSS solution for those tasks where submetric accuracy is enough, such as CAP OTSC.