Japan: The Strategy Headquarters for Space Development, Japan decided to develop a Japanese version of the Global Navigation Satellite System (GNSS). The envisaged system is expected to stimulate various industries in Japan. The US, operator of the existing GPS network, welcomed the idea of linking up with a Japanese counterpart from a security point of view.
The envisaged Japanese system would cover mainly the Japanese archipelago and surrounding areas. Four to seven quasi-zenith satellites would be launched for the system, which would fly above Japan and Australia in figure-eight loops.
This system has a few advantages. For instance, since at least one satellite would be above Japan at all times, there should be no blind spots. Also the accuracy of positioning would be improved, with the margin of error reduced to one meter or less.
Source: www.yomiuri.co.jp