SBAS

SBAS (Satellite-Based Augmentation System) augments GNSS signals with correction data broadcast by geostationary satellites, improving position accuracy, integrity, and availability for aviation use.

Regional SBAS systems:

WAAS (USA)
EGNOS (Europe)
MSAS (Japan)
GAGAN (India)

SBAS enables LPV approaches with decision heights as low as 200 ft without ground-based navigation aids, providing ILS-equivalent capability using only satellites.