| 摘要 |
PROBLEM TO BE SOLVED: To measure a present position without using GPS(global positioning system), etc., by selecting specified corresponding map information based on area designating information and calculating present position information as a position in the map information. SOLUTION: CPU 8 fetches an area number and an additional ID, refers to map position information table and retrieves a map number correspponding to the area number. Moreover, it is discriminated to which place of subdivided sections in map data of the corresponding map number the position indicated by the received area number and the additional 10 corresponds and the latitude and longitude of the subdivided section is calculated. Then, after the latitude and logitude of the present position are calculated, navigation display is executed. That is, a map in the periphery of the present position is displayed through the use of map data of the corresponding map number, etc., and also marking display for indicating the present position in the map display is executed in a display part 11. |
