Angular velocity calculating apparatus for navigation apparatus

An angular velocity calculating method, comprising the steps of:

• detecting plural velocities of a moving matter at plural positions on said moving matter, respectively;
• deriving a value of a parameter which determines an angular velocity of the moving matter;
• and
• calculating an angular velocity of the moving matter based on the value of the parameter, wherein said deriving step comprises the steps of:
• deriving a first value for the radius;
• calculating an angle of movement of the moving matter;
• calculating a distance of a projection between the plural velocity detectors;
• calculating a second value of said radius;
• and
• comparing a value of said first value of said radius with the second value of said radius.

A navigation apparatus, comprising:

• first and second velocity detectors mounted on a vehicle for acquiring first and second velocities of said vehicle;
• a velocity calculating unit for determining a mean velocity of the vehicle based on the first and second velocities;
• a processing unit for deriving a radius of movement of the vehicle based on the first and second velocities;
• an angular velocity calculating unit for determining the angular velocity of the vehicle based on the radius of movement derived by the processing unit;
• a central processing unit for obtaining a current position of the vehicle based on the mean velocity of the vehicle and the angular velocity of the vehicle;
• a storage device for storing map information;
• and
• a display;
• wherein said central processing unit reads map information from the storage device and provides data to the display so that the display indicates the current position of the vehicle superimposed on the map information.