| 摘要 |
To enable positional information to be provided even if a signal intensity of a received GPS signal is low by compensating a phase inversion of a navigation message and performing a phase integration over a long period. A base station 20 continuously receives the GPS signal 11 and extracts therefrom information for supporting reception and positioning computation in a GPS receiver 30 and retains the information. The base station 20 transmits the support information to the GPS receiver 30 via a communication line 40 when the GPS receiver needs the information. The base station 20 supports reception time synchronization in the GPS receiver 30. The GPS receiver 30 receives the GPS signal 11, generates an intermediate frequency signal through down-conversion, and then stores an A/D conversion data in a memory unit. In the GPS receiver 30, the GPS signal data stored in the memory unit 33 is subjected to integration with phase of the GPS signals aligned based on the support information (satellite navigation message and phase inversion information) supplied from the base station 20, and then positioning computation is performed using the integral GPS data.
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