| 摘要 |
PURPOSE:To shorten the recapture time of a satellite radio wave by executing position measuring data, etc. of GPS immediately before receiving the satellite radio wave, and forecasting a receiving carrier frequency of a varied GPS and a PN code phase. CONSTITUTION:In case when a radio wave from a satellite has been shielded by a tunnel, etc., a magnetic direction indicator 14 and a range finder 18 is utilized. In this case, position measuring data of immediately before position measurement becomes impossible is led into an assumed position operator 44. Accordingly, the operator 44 calculates an assumed position of this automobile 10 by referring to the position measuring data as a reference, and based on data of the magnetic direction indicator 14 and the range finder 18. On the other hand, the position measuring data of immediately before the position measurement becomes impossible, and a data input signal of the direction indicator 14 and the range finder 18 are led into a carrier frequency code phase operator 46. In this way, when data from the operator 44 is led into the operator 46, a carrier frequency of a satellite and a code phase can be forecast and calculated. Accordingly, the recapture of a satellite wave can be executed in the shortest time. |
