GBAS and SBAS Transmission RNAV

Both GBASGBAS —Ground Based Augmentation System and SBASSBAS —Space Based Augmentation System ground stations identify any errors in the GPSGPS —Global Positioning System (USA) signal by comparing their known position to their GPSGPS —Global Positioning System (USA) position. The difference between the two is then transmitted to aircraft. The signature difference between SBASSBAS —Space Based Augmentation System and GBASGBAS —Ground Based Augmentation System is that GBASGBAS —Ground Based Augmentation System uses VHFVHF —Very High Frequency to transmit the correction directly whereas SBASSBAS —Space Based Augmentation System transmits it via geostationary satellites. SBASSBAS —Space Based Augmentation System thus has a far wider range in which the corrections can be received.