Abstract: A navigation system is provided for offering navigational assistance to a mobile user. The navigation system receives GPS position information signals which are processed to determine current position latitude and longitude coordinates and direction of travel. A destination database includes a plurality of categorized destinations and corresponding destination position coordinates pertaining to the destinations. The destination database is stored on an interfacable memory card and contains menu categories and subcategories for classifying the destinations and additional text information pertaining to the destinations. User selectable menu controls enable the user to sequence through the menu of categories and destinations and select a desired destination. This is easily accomplished by rotating a rotary pushbutton to view category and destination selections and depressing the rotary pushbutton to select the selection shown.

Abstract: A navigation system is provided for offering navigational assistance to a mobile user. The navigation system receives GPS position information signals which are processed to determine current position latitude and longitude coordinates and direction of travel. A destination data base includes destination related information preferably stored on an interfacable memory card and contains menu categories and subcategories for classifying destinations and text information. The memory card may include a user modifiable data base. Data information is provided with a data identification code which is required to match the user identification code assigned to a given system for authorized access thereto. Such data could be provided for a period of time set to expire. User selectable menu controls enable the user to sequence through the menu of categories and destinations and select a desired destination.

Abstract: A system and method of automatically calibrating a vehicle speed sensor signal to provide an accurate speed signal for use in vehicle systems such as a navigation system. The navigation system receives GPS position information signals which are processed to determine current position. A compass provides an indication of the vehicle heading. The navigation system receives the vehicle speed sensor signal and counts the number of signal pulses during a time period. The system determines a pulse ratio of the vehicle speed sensor as a function of a GPS determined speed and the pulse count. The pulse ratio is subsequently used to calibrate the vehicle speed sensor signal. With the navigation system, the calibrated vehicle speed signal is used in connection with a dead reckoning technique for determining the position of the vehicle when GPS signals are unavailable.

Abstract: A navigation system is provided for offering navigational assistance to a mobile user. The navigation system receives GPS position information signals which are processed to determine current position latitude and longitude coordinates and direction of travel. A destination database includes a plurality of categorized destinations and corresponding destination position coordinates pertaining to the destinations. The destination database is stored on an interfacable memory card and contains menu categories and subcategories for classifying the destinations and additional text information pertaining to the destinations. User selectable menu controls enable the user to sequence through the menu of categories and destinations and select a desired destination. This is easily accomplished by rotating a rotary pushbutton to view category and destination selections and depressing the rotary pushbutton to select the selection shown.