Japan: Mitsubishi Electric, the prime contractor of Japan’s Quazi-Zenith Satellite System, has informed media that it is on track to launch the first commercial, nationwide, centimeter-scale satellite positioning technology.
In QZS-1 trial tests, the average accuracy is about 1.3 centimeters horizontally and 2.9 cm vertically. To carry out highly precise satellite positioning, distances from the Geospatial Information Authority of Japan'sGNSS-based control stations are calculated using data from these control stations. The Quazi-Zenith Satellite System (QZSS) is a constellation of Japan's positioning satellites which will have geosynchronous orbit with inclination of 45 degrees in order to pass near the zenith over Japan.
The expansion of the Quasi-Zenith Satellite System (QZSS) will be carried out via a $526 million contract with the company Mitsubishi Electric, which will build three navigation satellites to be launched by the end of 2017. Two of these satellites will be placed in inclined orbits, the third one will operate in geostationary orbit over the equator. The three new satellites will join Japan's first QZSS satellite, Michibiki, launched in September 2010, thus forming a four-satellite constellation.
According to the Japanese government's Office of National Space Policy, GPS signals are currently only available about 90 percent of the time in Japan, but once the system is complete satellite navigation will be possible 99.8 percent of the time.