| 摘要 |
PROBLEM TO BE SOLVED: To provide a navigation apparatus that performs route guidance processing in highlands where a hard disk drive is unavailable even when the storage capacity of a semiconductor memory is small. SOLUTION: When the current height exceeds the available upper limit height of the hard disk drive 40 (S1: Yes), map data is transferred to a DRAM 50 (S4). The storage capacity of a highlands map data storage area 54 of the DRAM 50 and the data amount of the map data to be transferred from the hard disk drive 40 are compared with each other. When the storage device of the highlands map data storage area 54 is smaller, the data amount of the data to be transferred with attribute data removed is set to be no more than the storage capacity of the highlands map data storage area 54 in ascending order of priority in the route guidance. This allows route guidance processing to be performed in highlands where the hard disk drive 40 is unavailable even when the highlands map data storage area 54 of the DRAM 50 is small. COPYRIGHT: (C)2009,JPO&INPIT |
