Michibiki Satellite-based Augmentation Service

Michibiki Satellite-based Augmentation Service (MSAS), formerly Multi-functional Satellite Augmentation System, is a Japanese satellite based augmentation system (SBAS), i.e. a satellite navigation system which supplements the GPS system by reporting (then improving) on the reliability and accuracy of those signals.

Source: Wikipedia — Michibiki Satellite-based Augmentation Service (CC BY-SA 4.0)