| 摘要 |
PROBLEM TO BE SOLVED: To provide a positioning device etc., which select a pseudo-distance calculating method by grasping a position error at an early position accurately. SOLUTION: The device comprises: a relative position calculating means calculating a position Ps on the satellite orbital of an SPS satellite at the present time relating to the early position PO for positioning; a predicted receiving frequency calculating means calculating a predicted receiving frequency from the satellite with predicting a Doppler shift based on the moving state of the SPS satellite relating to the early position PO; a frequency difference calculating means calculating the difference between a predicted receiving frequency and a measured receiving frequency of an actual receiving frequency; an early position error calculating means calculating the early position error POer, based on the relative position and the frequency difference DPer; and a positioning method selecting means selecting either the first positioning method of calculating a pseudo-distance by using a code phase of the satellite signal, based on the early position error POer, or the second positioning method of calculating the pseudo-distance by using a retarding time of the satellite signal. COPYRIGHT: (C)2008,JPO&INPIT
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