| 摘要 |
A GPS positioning system has: at least one mobile station to measure a positional coordinate by receiving radio wave from a satellite; a plurality of fixed stations that have predetermined positional coordinates and receive radio wave from the satellite; and arithmetic processing means, which is connected with at least one mobile station and a plurality of the fixed stations by communication, that selects an appropriate fixed station based on positioning data transmitted from at least one mobile station, and transmits reference positioning data of the fixed station selected to the mobile station. <??>A data server for GPS positioning has: a first communication interface, whose positional coordinate is fixed at a known point, that receives positioning data from a plurality of fixed stations that receive radio wave from a satellite; a second communication interface that receives positioning data from a mobile station whose positional coordinate is measurable by receiving radio wave from the satellite; and arithmetic processing means that selects an appropriate fixed station out of a plurality of the fixed stations based on the positioning data received via the second communication interface. <IMAGE> |
