Abstract
It is allowed to use SBAS (satellite-based augmentation system) for non-aviation applications while it was originally developed as a GPS augmentation system for aviation purpose. The SBAS signal broadcast from geostationary orbit is quite attractive to transmit various information useful for non-aviation users beyond wide-area differential information. Types and contents of SBAS messages are, however, fixed in the SBAS standard, so it might be necessary to transmit non-standard message for some applications. This paper describes potential methods to transmit non-standard messages for SBAS with SBAS-capable avionics kept safe against these messages. In addition to using undefined message types, detail analysis is given to the method using the different CRC parity.
