Abstract: A data storage medium storing a representation of a topological structure having topological features, on which is stored a digital data base including a plurality of carrier blocks of data representing the topological features t a given level of detail, each one of the carrier blocks being a representation of a carrier which is a closed set containing in its interior a given topological object. Also disclosed are methods for building the carrier blocks, for building a hierarchy of carrier blocks, and for searching the digital data base at all hierarchical levels.

Abstract: A computer hardware and software system and method for displaying a map of streets corresponding to an area over which a vehicle may move to assist a driver to navigate, the system displaying the map on a display based on a scale-dependent street prioritization scheme, providing on the display a vehicle position symbol indicating the current position and heading of the vehicle and a moving map which moves in translation and rotation as the vehicle moves, selectively and dynamically labelling streets on the display as the vehicle moves, and providing a destination symbol on the display indicating a desired destination or the direction to a desired destination.

Abstract: A vehicle navigational system and method for tracking a vehicle, including a programmed computer, sensors for sensing the distance traveled and heading of the vehicle, and a stored map data base identifying a map of an area over which the vehicle is moving, in which the computer calculates and advances dead reckoned positions of the vehicle in response to distance and heading data, provides data identifying a contour of equal probability containing the dead reckoned positions and having a probability of containing the actual location of the vehicle, derives multiparameters from the map data base, and updates a given dead reckoned position and the contour using a highly developed vehicle navigational algorithm if a more probable dead reckoned position exists based upon the given dead reckoned position, the contour and the derived multi-parameters.