DATA FOR ROUTE SEARCH IN ELECTRONIC MAP DATA, DATA STRUCTURE IN DATA FOR ROUTE GUIDE, AND THEIR UTILIZATION

摘要

PROBLEM TO BE SOLVED: To achieve route search and route guidance even if new and old data are included in electronic map data in a navigation apparatus.;SOLUTION: The data for route search and those for route guidance can be upgraded in a prescribed rectangular region unit. They are composed of upper- and and lower-layer data having different coordinates systems. The upper-layer data have a sub key for specifying a coordinates value in a lower layer by prescribed calculation other than a coordinates value in an upper layer. The navigation apparatus specifies a node and a link for performing route search and route guidance by using the sub key for specifying the coordinates value when the version of the upper-layer data differs from that of the lower-layer data.;COPYRIGHT: (C)2004,JPO