Japan has successfully launched the fourth satellite from the Tanegashima Space Center that will be part of its own GPS alternative, which should enable very precise positioning with an accuracy of a few centimeters.
A Japanese H-2A rocket from Mitsubishi Heavy Industries successfully launched the satellite into space. The satellite is part of the so-called Quasi-Zenith Satellite System, a positioning system for civilian purposes. The fourth QZSS satellite will work together with three previously launched satellites and the American GPS satellites.
Ultimately, the Japanese satellites must also function without cooperation with the GPS satellites. The accurate positioning should be operational sometime in 2018; at the moment the system is still in a test phase. A total of seven QZSS satellites are to be placed in orbit, which should probably enable the system to function independently of the GPS system by 2023.
The intention is that the satellites will enable very accurate positioning in, for example, the densely populated Japanese cities, where tall buildings sometimes block GPS signals. The satellites should also stimulate self-driving cars and, for example, applications in precision agriculture. The Japanese government is also studying the possibilities for military applications.
The four satellites are not geostationary and therefore do not stand still relative to the earth’s surface. The satellites are in orbit around the earth, moving in a figure-eight relationship with respect to the ground. That way there is always a satellite directly over Japan.
The European GPS alternative Galileo went live in December 2016. The system is expected to be fully operational in 2019. By 2020, all 30 planned satellites will be in orbit. Galileo is a system of the European Union and the European Space Agency ESA. There are now various systems for location determination with satellites. In addition to the US GPS, Russia has Glonass, China has BeiDou and India has Irnss.