Positioning with GPS is widely used in Japan in the areas of car navigation, human navigation, and surveying.

    GPS suffers some difficulties, as users in mountainous and urban areas cannot receive signals from a sufficient number of GPS satellites for positioning because of shadowing, and so cannot receive positioning services in any place and at any time. Also positioning accuracy with GPS may not be sufficient for high-speed transportation such as trains or cars. A new satellite positioning technology is needed.

    ENRI is studying correction technology for highly accurate and reliable positioning with a high-elevation satellite (QZSS quasi-zenith satellite system) combined with GPS. GPS may be improved in positioning accuracy and reliability and used more safely with this correction technology.