SBAS (Satellite-Based Augmentation System) improves GPS by providing:

Integrity, accuracy, and availability corrections via geostationary satellites

Correct

Additional ranging signals only

Ground-based localizer signals

Inertial navigation backup

Explanation

SBAS uses geostationary satellites to broadcast GPS correction data, integrity information, and additional ranging, enabling precision approaches.

Test yourself with random questions from Radio Navigation and all other ATPL subjects.