GPS NETWORK SYSTEM, GPS TAG, MOBILE STATION AND CORRECTION DATA RELAY STATION

摘要

[PROBLEMS] Low cost, precise and high speed global positioning can be carried out in a region where no electromagnetic wave from a GPS satellite can be received. [MEANS FOR SOLVING THE PROBLEMS] A GPS network system for measuring a position by means of a GPS is provided with a GPS tag (100) for transmitting an electromagnetic wave to measure a position, and a mobile station (300) for receiving the electromagnetic wave from the GPS tag (100) with which a position is measured. The GPS tag (100) sets up and holds correcting data for GPS position measurement. The GPS network system is further provided with a correction data relay station (200) for relaying the correction data from the mobile station (300) while maintaining consistency of the correction data with the GPS tag (100).