QZSS – Quasi-Zenith Satellite System

QZSS is a Japanese regional satellite navigation system that enhances GPS performance, especially in urban and mountainous areas. It uses satellites in quasi-zenith orbits to ensure at least one satellite is nearly overhead at all times over Japan. The system provides high-precision positioning services, such as the Centimeter-Level Augmentation Service (CLAS), and supports satellite-based augmentation systems like MSAS. QZSS is integrated into Japan’s geodetic infrastructure, contributing to precise measurements and monitoring of Earth’s crustal movements.

More Info: https://qzss.go.jp/en