MAP ACQUISITION SYSTEM, MAP ACQUISITION APPARATUS, NAVIGATION APPARATUS HAVING MAP ACQUISITION APPARATUS

摘要

PROBLEM TO BE SOLVED: To provide a map acquisition system capable of properly acquiring momentarily useful map data in the course up to a destination in such a manner that the sufficient map data map be acquired despite of a limited communication capability and the memory capacity on a vehicle side. SOLUTION: This on board map acquisition apparatus acquires the plural maps A to D for respectively different scales from the information center via the communication means. The map A of a wide range for the large scale is acquired at a starting point distant from the destination. Route guiding is executed by using the map A. The vehicle arrives at a map acquisition place on approaching the destination to some extent and the map B for the smaller scale is acquired. The maps for the smaller scales are acquired the nearer the destination. Then, the map data for the scales suitable for the places are acquired at the respective places to the destination. Since there is not transmission of a large quantity of the data at one time, the sufficient maps are obtainable with the limited communication capability and the smaller map memory capacity on the vehicle side is necessitated.