| 摘要 |
PROBLEM TO BE SOLVED: To provide a position detection system capable of detecting an accurate position, even in an indoor site, a subway or the like incapable of receiving a GPS signal from a GPS satellite. SOLUTION: A satellite time correction factor bias term as to time error correction out of a navigation message included in the GPS signal from the GPS satellite demodulated by a navigation message demodulating part 22 is recalculated by a satellite time correction parameter recalculation processing part 23 to simulate an installation position of an indoor antenna for retransmitting it to a radio wave arrival incapable space, and recalculated one is corrected as the navigation message for the retransmission. The corrected navigation message is modulated thereafter into an IF signal by a navigation message remodulation part 24, and is further up-converted into a corrected GPS signal of an L-band with the signal format same to that of a GPS positioning signal from the GPS satellite by an L-band frequency conversion/amplification part 25, so as to be output from the indoor antenna. A simulated GPS signal equivalent to the corrected GPS signal may be generated to be output, assuming that the GPS signal is received in a specified position. COPYRIGHT: (C)2008,JPO&INPIT |
