Patent ID: 6415227
Filing Date: 2002-07-02
Classification: G01C,G01S

Abstract:
An enhanced global positioning system and map navigation process, comprising said steps of:(a) receiving a measured position from a global positioning system receiver; (b) retrieving geospatial data from a geospatial map database based on said measured position from said global positioning system receiver by using a tile index file, wherein said tile index file stores geographic extent information of tiles which are geographically subdividing a coverage solely for a purpose of enhancing data management; wherein a geographic extent of an access area is compared with said geographic extent of said tiles to derive a plurality of involved tiles for said access area; (c) performing time-space filtering based on said measured position and said retrieved geospatial data from said geospatial map database to derive a displaying position for a user; wherein said measured position and a previous position and a previous velocity are used to derive a true position for said user; and (d) displaying a trajectory of said user on a graphic displaying unit, which tracks a motion of said user.