Abstract: An in-vehicle navigator comprises a map memory unit for memorizing road map data consisting of road data comprised of the combination of nodes and links, and background data such as buildings, a location detection unit for detecting a vehicle location, an initialization unit for inputting a destination, and route calculation conditions desired by a vehicle operator, and a route calculation unit for reading road map data containing a current location and the destination from the map memory unit. The route calculation unit also calculates a recommended route, based on the read road map data from the map memory unit and the read route computation conditions from the initialization unit. The navigator further comprises a memory unit for storing the recommended route, and a vehicle guidance unit for detecting an approach to a junction on the recommended route, based on the vehicle location.

Abstract: In a location detecting apparatus which detects the location of a moving body on the basis of the heading signal from a terrestrial magnetism heading sensor attached to the moving body and the rotational angle signal from a rotational angle sensor attached to the moving body, a correcting method for correcting errors in a terrestrial magnetism heading sensor, comprising the steps of: detecting the amount of a heading change of the moving body that is made when the moving body turns a curve, and detecting a magnetized amount of the moving body on the basis of the detected amount of a heading change, an output from the terrestrial magnetism heading sensor before the heading change is made and an output from the terrestrial magnetism heading sensor after the heading change is made.

Abstract: A vehicle location detecting method for detecting the location of a vehicle within a predetermined area, comprising the steps of: outputting distance data at every predetermined interval, the distance data being representative of the distance that a vehicle has traveled, outputting heading angle data at every predetermined interval, the heading angle data being representative of the heading angle change of vehicle travel, storing road map data representative of roadways, computing a present location data from the distance data and the heading angle data, and a limit error of the present location data which is determined by errors in the distance data, in the heading angle data and in the road map data, and registering locations on the roadways, which roadways are located within the limit error of the present location data, as estimate locations, computing correlation coefficients corresponding to the registered estimate locations, and selecting a correlation coefficient whose error is smallest with respect to