A navigation method and system for extracting point of interest (POI) data
from a map data source and sorting the POIs by distance from a current
user position to display the same at high speed without requiring a large
memory. The navigation system aligns the cells each having specified POI
in an cell array and classifies the cells into a plurality of different
levels based on distance (first sorting operation) from the current user
position, or positions of the cells in the cell array relative to the
cell closest to the user position. The navigation system extracts the
POIs from the cells in the specified level, sorts the POIs by distance
(second sorting operation), and displays the POIs. During each process,
the navigation system retrieves and processes only a small amount of POIs
sufficient for the current display screen and immediate scrolls of few
pages.