MSAs

MSAS, the MTSAT Satellite-based Augmentation System, is a satellite-based augmentation system (SBAS) developed by Japan to enhance the performance of global navigation satellite systems, principally the Global Positioning System (GPS), for civil aviation. It provides additional integrity, accuracy, and availability information to GPS signals, enabling more reliable navigation within its coverage area and supporting precision approach procedures.

The system consists of a network of ground reference stations across Japan and surrounding regions, a Master Control Center that processes data and generates correction and integrity messages, and geostationary satellites that broadcast these messages to users. MSAS signals are designed to be compatible with standard SBAS receivers and can be used with GPS to improve navigation performance.

MSAS is part of the broader SBAS family, alongside systems such as WAAS in the United States and EGNOS in Europe. It is intended to be interoperable with GPS and other GNSS signals to enhance aviation safety and efficiency, particularly for en-route navigation and instrument flight procedures that require higher integrity and accuracy.

Administration and development of MSAS are overseen by the Japan Civil Aviation Bureau (JCAB) and the Ministry of Land, Infrastructure, Transport and Tourism (MLIT). The system has evolved through updates to increase coverage, integrity monitoring, and broadcast performance, aligning with international SBAS standards to support international aviation operations in the Asia-Pacific region.