Patent ID: 8645054
Filing Date: 2014-02-04
Classification: G01C,G09B

Abstract:
1. A navigation system comprising: a map database that stores map information, broadcast wave receivable area information indicating an area capable of receiving a broadcast wave, and broadcast wave reception blocked area information indicating an area incapable of receiving the broadcast wave; a current position detecting unit for detecting a current position; a control unit for estimating a direction of travel from the current position detected by the current position detecting unit, and for deciding, from the broadcast wave receivable area information and the broadcast wave reception blocked area information acquired from the map database, as to whether the area capable of receiving the broadcast wave continuously exists in the direction of travel estimated; and an output unit for producing a message indicating existence of the area capable of receiving the broadcast wave continuously in response to a decision result of the control unit, wherein, the control unit comprises a guidance route arithmetic unit for searching for a route which connects the current position to a destination and is capable of receiving the broadcast wave continuously according to the broadcast wave receivable area information and the broadcast wave reception blocked area information acquired from the map database; and the output unit shows the route searched for by the guidance route arithmetic unit, and produces a message indicating whether the route searched for includes the area incapable of receiving the broadcast wave continuously or not.