EGNOS signals are transmitted via geostationary satellites

Around 50 stations dotted around Europe monitor the current status of satellite navigation signals across the continent and their findings are used as the basis for a ‘correction’ message which serves to sharpen the precision of positioning fixes while also advising on their ‘integrity’, or ongoing reliability. These correction messages are uplinked to geostationary satellites for rebroadcast to all EGNOS-equipped receivers, which are mostly deployed in safety-critical applications such as civil aviation, maritime and agriculture.