Quasi-Zenith Satellite System

The Quasi-Zenith Satellite System (QZSS) is a Japanese satellite positioning system composed mainly of satellites in quasi-zenith orbits (QZO). Satellite positioning systems use satellite signals to calculate position information. The QZSS is sometimes called the “Japanese GPS.” Complements GPS for satellite positioning, navigation and timing service that is more precise and stable.

QZSS is a system especially for usage in the Asia-Oceania regions, with a focus on Japan. The ideal would be to have satellites stand constantly still in the sky above Japan (the zenith as seen from the earth’s surface in Japan). For that reason, the QZO of QZSS is a figure-eight shaped orbit with north-south asymmetry. Satellites spend approximately 13 hours in the northern hemisphere and roughly 11 hours in the southern hemisphere, allowing them to remain near Japan for a long period of time. QZSS (Michibiki) has been operated as a four-satellite constellation from November 2018, and three satellites are visible at all times from locations in the Asia-Oceania region. QZSS can be used in an integrated way with GPS, ensuring a sufficient number of satellites for stable, high-precision positioning. QZS are compatible with GPS and receivers can be procured at a low cost, so it is expected that position information businesses utilizing geographical and spatial information will be developed.

Application

• Regional high-precision positioning
• Communication services
• Mobile apps