Patent ID: 6218980
Filing Date: 2001-04-17
Classification: G01C,G01S

Abstract:
In a navigation system for a vehicle including a navigation computer for generating a predetermined course, means for determining the distance of the vehicle from the terrain of which it is traversing, said distance determining means comprising radar means for directing radiation toward the terrain and for receiving a radar return back from the terrain, and means for storing at least one reference map in data form corresponding to the terrain over which the predetermined course is to traverse, the improvement comprising means for transforming the reference map data to simulated data based on at least a known distance of the vehicle from the terrain over which the vehicle is traveling and on simulated radar returns from the terrain at said known distance, means for comparing the simulated data to data representative of the actual distance from said terrain, and means for determining the position of said vehicle with respect to said map based on said comparison.