Abstract: A navigation system on an automobile has a GPS receiver for producing first positional data indicating the automobile position based on radio waves from GPS satellites, and a self-operating sensor for producing second positional data indicating the automobile position based on speed and orientation sensor signals. A data processor compares previous and present first positional data to determine whether the difference therebetween is equal to or smaller than a first predetermined value, and also determines whether a PDOP value of the present first positional data is equal to or smaller than a second predetermined value. The present first positional data and the second positional data are compared to determine whether the distance between the present position of the automobile as indicated by the present first positional data and the present position of the automobile as indicated by the second positional data is equal to or greater than a third predetermined value.

Abstract: A navigation apparatus having a GPS receiver obtain coordinates of the current position. A key point or points close to the current position are retrieved from a recording medium attached to the apparatus. The distance and direction from the current position with respect to the retrieved point are computed. The name of the retrieved point is then displayed along with the distance and direction with respect thereto.

Abstract: An on-board navigation apparatus which uses a driver having a changer function to selectively reproduce any of music- and map-containing storage media. When it becomes necessary to read map data during reproduction of a music-containing medium, the current medium is replaced with the applicable map-containing medium upon arrival of an intra-music interval. This allows one driver driving both music and map data media to read map data without interrupting the piece of music being reproduced.

Abstract: A point selecting apparatus for use in an on-board navigation system configured to display a map on a display on the basis of map data stored in a memory. The apparatus is characterized by the provision of a plurality of point-select keys, four cursor keys, a delete command key, a register command key, and a control means adapted to perform control operations to eliminate from the memory or register into the memory coordinate data of a point in the vicinity of a point indicated by the position of a cursor after a key entry of any one of the plurality of point-select keys, in response to a key entry of the delete command key or the register command key.

Abstract: An onboard navigation system for displaying a map in a scrolling manner while a mark showing the position of the vehicle is fixed. The system is adapted so that the fixed display position of the mark indicating the vehicle's position can be set at an arbitrary selected position, satisfying a user's demand for viewing a map of an area further ahead of the vehicle in the direction of the vehicle's movement.

Abstract: An on-board navigation apparatus having a GPS receiver detects a difference between the current and the previous values of the estimated current position in terms of the longitude and latitude information gained from GPS data. The difference is added to the coordinates of the previously established position, the result being taken for the coordinates of the estimated current position. This makes it possible to estimate the current position coordinates accurately even if the accuracy of GPS data is not high enough. When the GPS receiver is in a two-dimensional measuring state, the coordinates of the estimated current position are obtained from a manually or automatically designated elevation value and from the GPS data. This allows the current position coordinates to be estimated with accuracy even if the accuracy of GPS data has dropped due to the two-dimensional measuring instead of a three-dimensional measuring.

Abstract: A display device applied to a navigation system for a vehicle displaying map information by using a color pallet. The device comprises means for supplying at least a signal distinguishing a bright and a dark environment according to the degree of brightness degree in a passenger compartment of the vehicle. Color pallets have their contents changed according to the information from the supply means. The contents of the registers are changed so that a degree of brightness of background color of a display unit is decreased to less than a decreased degree of brightness of colors displaying the information on the display unit when the output information of the supply means changes from the brightness to the darkness.

Abstract: A momentarily changing position of a travelling vehicle is correctly identified by a vehicular nagivation system on which a magnetism sensor, angular velocity sensor, travel distance sensor and global positioning system are mounted. The current position of the vehicle is identified by, for example, storing data of a road on a map in the form of numerical values, measuring a predetermined distance which the vehicle has travelled and computing the current position on the road based upon the predetermined distance thus measured.

Abstract: The invention provides various methods for detecting the bearing of a moving vehicle and of processing data in a vehicular navigation system. Provided there is carried out a process of recognizing the present position of the vehicle while the vehicle is moving at a predetermined speed, bearing data obtained from a prestored map is utilized to determine the present position of the vehicle. At that time, the data output from a terrestrial magnetism sensor, which would otherwise be used, is discarded.

Abstract: A method for processing data received by a receiving device which outputs present location data for a movable vehicle based on the Global Positioning System and is positioned in the vehicle, including the steps of calculating an average of a predetermined number of data output from the receiving device while the vehicle stops, determining the average to be an effective data if the standard deviation of the data is within a predetermined range, and processing the averaged data as the present location data for the vehicle.

Abstract: A method for displaying a map, including steps of evaluating a start dot and an end dot of each segment defining a boundary of a predetermined area on the map, storing sequentially each of the evaluated data so that each of the segments has a lateral deflection with respect to the predetermined area, determining the lateral deflection of the predetermined area according to the evaluated data for the start and end dots of the segment when the predetermined area is painted on a display unit, calculating a start point for painting positioned inward of the segment and each of the evaluated data, and painting the predetermined area with a predetermined color from the start point.