| 摘要 |
PROBLEM TO BE SOLVED: To provide a positioning device and the like which can verify phase accuracy of positioning base signal to accurately position the signal even under weak electric field having feeble signal strength. SOLUTION: The positioning device 20 for receiving positioning base signal from sending source positions its current location. The positioning device 20 includes phase computing means which correlates replica positioning base signal generated by it with the above positioning base signal to compute phase of the positioning base signal; predictive phase computing means which estimates the present phase to compute predictive phase based on the previously-positioned phase, Doppler shift of radio wave frequency loaded with the positioning base signal, and elapsed time from the previous positioning; phase contrast evaluation means for determining whether phase contrast between current phase and predictive phase is within predefined allowable range of phase contrast or not; and positioning means which uses the phase within the allowable range of phase contrast to position the current location. COPYRIGHT: (C)2009,JPO&INPIT
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