QZSSjärjestelmää

The Quasi-Zenith Satellite System, or QZSS, is a four-satellite system developed and operated by the government of Japan. Its primary purpose is to enhance the accuracy and availability of the Global Positioning System (GPS) in Japan and surrounding East Asian and Oceanian regions. QZSS is a regional satellite navigation system that complements existing global navigation satellite systems (GNSS) like GPS, GLONASS, and Galileo.

QZSS provides a positioning service that is accessible with compatible receivers. It transmits signals on frequencies similar to GPS, allowing for seamless integration with existing GNSS devices. The system consists of geostationary satellites, which appear to remain in a fixed position in the sky, and highly elliptical orbit satellites, which spend a significant portion of their orbit over Japan. This unique orbital configuration ensures that at least one QZSS satellite is always visible from most locations within its coverage area, even in environments where satellite signals are typically obstructed, such as urban canyons or mountainous terrain.

The benefits of QZSS include improved positioning accuracy, reduced signal acquisition time, and enhanced reliability, especially in areas with poor satellite visibility. It supports various applications, including precision agriculture, disaster management, intelligent transportation systems, and location-based services. QZSS is also designed to provide augmentation services, such as precise point positioning (PPP) and real-time kinematic (RTK) corrections, to further boost positioning performance. Japan continues to develop and expand the QZSS capabilities, with plans for future enhancements and increased satellite constellations.