Patent ID: 6169516
Filing Date: 2001-01-02
Classification: G01C,G01S,G09B

Abstract:
A navigation system comprising: a topographical data memory storing a topographical data which provides topographical plane coordinates with altitude values of displayed components; a map data memory storing position and attribute information on map display components which include roads and names of places; an input unit which inputs display reference point position coordinates and viewing line directional angle by which the position and direction of displayed map are derived; a displayed region determining block which determines a region displayed on a screen in accordance with information issued from said input unit; a topographical geometric modeling block which reads from said topographical data memory a topographical geometric data on the displayed region determined by said displayed region determining block and carries out modeling of the topographical geometry by processing said topographical geometric data; a display reference point altitude determining block which determines an altitude value of the display reference point by processing both the information from said input unit and the information from said topographical geometric modeling block; a viewpoint coordinate determining block which determines a viewpoint coordinate by processing both the information from said input unit and said display reference point altitude determining block; a map component altitude determining block which reads from said map data memory a map display component within said displayed region and determines an altitude value of said map display component with reference to information from said topographical geometry modeling block thereby to produce a display graphic data; a coordinate transforming block which, based on both information from said viewpoint coordinate determining block and information from said input unit, applies a perspective-projection transformation to both information from said topographical geometric modeling block and information from said map component altitude determining block; a drawing process block which produces a stereoscopic map image by processing information from said coordinate transforming block; and an image display unit which actually displays said stereoscopic map image.