| 摘要 |
PROBLEM TO BE SOLVED: To more quickly detect a positioning signal. SOLUTION: Just after a device power source is turned on, a search is carried out over a predetermined frequency range, and in compliance with a search error unable to detect transmission signal even in this search, a search is carried out with the frequency range widened. In the device operation state other than that just after the input of the device power source, a temperature range is divided into a plurality of sections with respect to a frequency variation curve, and in each of the divided sections, a search is carried out while a frequency range to be searched is made to change, or alternatively, the frequency range is made to vary according to a change ratio of the peripheral temperature. |
