Storage medium on which geographical data of a geographical area are stored combined as map units, method for generating a map of the geographical data and navigation device

摘要

The present invention relates to a storage medium on which geographical data (20, B, P, U) of a geographical area are stored in aggregate as map units (17), a corresponding method for generating a map from the geographical data (20, B, P, U) and a corresponding navigation device. In order to reduce the amount of data to be processed, the map units are hierarchically structured, wherein n-th order map units each correspond to a geographic area, where n is a natural number, and map units of (n + 1) -th order each one geographical subarea of one of the subareas.