How do SBAS and GBAS differ in navigation accuracy and use?

How do SBAS and GBAS differ in navigation accuracy and use?

• A. SBAS provides regional corrections; GBAS provides local corrections for precision approaches.
• B. SBAS provides local corrections; GBAS provides regional corrections for GLS.
• C. SBAS provides regional corrections; GBAS provides local corrections for GLS.
• D. SBAS replaces GPS; GBAS uses GLONASS.

Answer: (A)

SBAS and GBAS are both GNSS augmentation systems, but they differ in how broad their corrections are and what they’re used for. SBAS sends corrections and integrity information from a network of ground stations up to geostationary satellites, which then broadcast region-wide (regional) corrections to a wide area. This improves GPS accuracy and reliability over a large region and supports various aviation operations, including approaches with vertical guidance, but not at the airport’s immediate vicinity with the highest precision. GBAS, on the other hand, is deployed at a specific airport. It uses local ground-based corrections computed from nearby reference stations and transmits them to aircraft in the local airspace, enabling highly precise, airport-specific precision approaches known as GLS. So the best description is that SBAS provides regional corrections, while GBAS provides local corrections for GLS. GBAS GLS is targeted at a single airport, delivering the highest local accuracy for precision approaches.

SBAS and GBAS are both GNSS augmentation systems, but they differ in how broad their corrections are and what they’re used for. SBAS sends corrections and integrity information from a network of ground stations up to geostationary satellites, which then broadcast region-wide (regional) corrections to a wide area. This improves GPS accuracy and reliability over a large region and supports various aviation operations, including approaches with vertical guidance, but not at the airport’s immediate vicinity with the highest precision.

GBAS, on the other hand, is deployed at a specific airport. It uses local ground-based corrections computed from nearby reference stations and transmits them to aircraft in the local airspace, enabling highly precise, airport-specific precision approaches known as GLS.

So the best description is that SBAS provides regional corrections, while GBAS provides local corrections for GLS. GBAS GLS is targeted at a single airport, delivering the highest local accuracy for precision approaches.