ABSTRACT
Japan is developing its regional navigational satellite system, called the Quasi-Zenith Satellite System (QZSS) as one of its primary space projects. The project officially started in 2003, following the proposal by the Japan Business Federation (Keidanren) in 2001 and the subsequent report by the specialized committee of the Council for Science and Technology (now Council for Science, Technology, and Innovation) endorsing the project.1 The most recent Basic Plan on Space Policy of Japan confirms the commitment to advance the project further for both civil and national security purposes. The aim of QZSS is to complement and augment the Global Positioning System (GPS) of
the United States (US). Its basic idea is to form a constellation of a minimum of three satellites on the geosynchronous orbit (GSO) on different planes, so that at least one of them is observed from Japan’s near zenith all the time. The high elevation angle is considered important, because tall buildings in the cities and high mountains in the rural areas can hinder observation of a satellite if it is on the low elevation angle.2 The first satellite “Michibiki” was launched on September 11, 2010 with the aim of technological validation. The current plan is to realize the constellation of four satellites by the end of the fiscal year 2017, which will be expanded to a constellation of seven by 2023.3
As to the legal framework, the Basic Space Law stipulates that the government shall take necessary measures to use satellites for the “improvement of the lives of the citizenry”, and refers to the promotion of information systems on positioning as one of such measures.4
