| 摘要 |
<P>PROBLEM TO BE SOLVED: To reduce the power consumption and the required time to automatically obtain the time difference information required to obtain the current time which uses the time information contained in a GPS signal. <P>SOLUTION: A position information shows each of the areas where the standard times adopted are different each other, and the position information according to the ECEF orthogonal coordinate system that is the standard of GPS and the time different information at the standard time in each of the areas against UTC, that is the standard of GPS, are stored beforehand, by associating in a city information memory unit 4. When the current time is to be obtained, a GPS-receiving unit 3 obtains the positional information indicated by the ECEF orthogonal coordinate system. A control part 7 obtains the time difference information corresponding to the position information directly from the city information memory unit 4, and by using the obtained time difference information, correct the current time indicated by the time information included in the GPS signal. Power consumption and the time required can be reduced, by eliminating the conversion treatment from the ECEF orthogonal coordinate system to the geodetic coordinate system, which is under normal times unnecessary in obtaining the current time. <P>COPYRIGHT: (C)2010,JPO&INPIT |
