Japan Plans Commercial Centimeter Accurate GNSS
Engineers at Tokyo-based Mitsubishi Electric Corp. report that they’re on track to start up the first commercial, nationwide, centimeter-scale satellite positioning technology.
Quazi-Zenith Satellite System (QZSS), will work alongside the U.S. GPS system, meaning data in Japan will be at the centimenter level, not the metres or so gpS provides without correction.
The Japanese goverment has set aside US $B1.7 for the seven satellites and 1200 ground stations. One satellite is in orbit, with two more expected by 2017. The final three will follow in later years. A company, Quazi-Zenith Satellite System Services, has been set up just to develop and run the ground system.
All of the correction will be done in real time and receivers will need a good sized antenna to receive the data. Test now confirm average accuracy of 1.3 centimeters horizontally and 2.9 cm vertically.
What will the Japanese use the extra accruacy for?
Besides pointing out obvious uses like mapping and land surveying, Sam Pullen, a senior research engineer in the department of aeronautics and astronautics at Stanford, says precision farming and autonomous tractor operations will be big applications. “Unmanned aerial vehicles and autonomous vehicles in general,” he adds, “will also find centimeter-level positioning valuable in maintaining and assuring separation from other vehicles and fixed obstacles.”
The constellation will also be used to send emergency messages when terrestrial communications are knocked out. Remember too that Japan has a number of big cities with tall building and mountains, so it suffers from "urban caynon" issues as we do here in areas like New York City.
Image from QZSS Brochure.