SBAS Retranslation / Pseudolite System for Precision Approach and Air Navigation

MichaƂ Rutkowski

The European Union has deployed EGNOS in part to provide for safe, costefficient alternative to instrument landing systems (ILS). Due to the fact that the EGNOS satellites travel in geosynchronous orbit, not every airport can truly benefit from the current system. At those located in the far north, in the mountains, or in highly urbanised areas, safe landings with EGNOS assistance can be impossible due to a lack of signal coverage. This idea presents possibilities for every airport in Europe by incorporating a Satellite Based Augmentation System (SBAS) retranslation pseudolite. With a retranslation station acting as an artificial satellite on the ground, SBAS corrections can be received from the peak of the nearest mountain and retransmitted to the approaching aircraft to ensure safe landing. Similar systems provide their own DGPS corrections through additional VHF data links, but this entails additional equipment. The proposed system is innovative in that it always provides up-to-date EGNOS services using the L1 band as a pseudolite. Users do not need any additional equipment to receive DPGS corrections and can benefit from them even at the ground level. This system is intended to work with any SBAS system and receiver.