| 摘要 |
PROBLEM TO BE SOLVED: To provide a navigation system which can inform a user that a vehicle has approached an administrative district boundary, and inform the user beforehand of the name of an approached new administrative district. SOLUTION: Administrative district data have a polygon showing an area of each administrative district, and at least the name of the administrative district. A route searching server 30 includes an estimated position calculation means 37 and an administrative district discrimination means 38, and the estimated position calculation means calculates an estimated position in the front as far as a threshold distance on a route along which a terminal device 20 is moving, based on the prescribed threshold distance set beforehand and the present position of the terminal device 20, and the administrative district discrimination means 36 obtains administrative district data to which the present position belongs and administrative district data to which the estimated position belongs, and discriminates whether each administrative district agrees with each other or not. When the administrative district discrimination means 36 discriminates disagreement of the administrative districts, the terminal device 20 is informed of approaching an administrative district boundary together with the name of the administrative district to which the estimated position belongs. COPYRIGHT: (C)2011,JPO&INPIT |
