Navigation apparatus, operation control method, and mobile terminal apparatus

A navigation apparatus including a geomagnetic sensor that detects a geomagnetic field of the navigation apparatus, an orientation calculation unit that calculates an orientation of the navigation apparatus based on the detected geomagnetic field, a cradle detection unit that detects that the navigation apparatus is connected to a cradle, and outputs a signal indicating that the navigation apparatus is connected to the cradle, and an operation control unit that receives the signal output from the cradle detection unit, and controls the orientation calculation unit to not detect the orientation of the navigation apparatus based on the detected geomagnetic field.