Receivers for Aviation

To receive EGNOS an SBAS capable receiver is required to decode and use the signals broadcast by the EGNOS system. An EGNOS receiver is based on a GPS receiver and contains additional processing to track and monitor the EGNOS Geostationary satellites and decode the information broadcast on them.

In order to decode and use the EGNOS signals for aviation purposes, an SBAS receiver needs to be certified by the relevant Technical Standard Order (TSO) which specify that SBAS receivers shall be compatible with the avionics standard RTCA Do-229C. Receivers complying with these standards are fully EGNOS compatible. There are two TSO's currently available: TSO-C145a is the "Airborne Navigation Sensors Using the GPS Augmented by the Wide Area Augmentation System" and TSO-C146a is "Stand-Alone Airborne Navigation Equipment Using the GPS Augmented by the Wide Area Augmentation System".

EGNOS is currently under an Initial Operations Phase and as such is broadcasting a test signal which prohibits the use of EGNOS for safety of life purposes. Therefore the use of EGNOS is currently at the users own risk and is not authorised for safety of life applications (see disclaimer on home page)

Satellite Based Augmentation Systems (SBAS) receivers are already certified in the USA. The EGNOS system equivalent, Wide Area augmentation System (WAAS), has been commissioned since July 2003. Certified receivers are being used on the growing aviation market. The first two certified aviation receivers are the GNS-480 from Garmin, and the EFIS from Chelton.