Patent ID: 8571795

Claim:
A navigation apparatus comprising: travel direction acceleration calculation means for calculating a mobile object's acceleration in the direction of the mobile object's motion, based on the mobile object's speed calculated from information received from a satellite; lateral acceleration calculation means for calculating lateral acceleration whose direction is perpendicular to the mobile object's motion, based on the mobile object's speed and direction calculated from information received from the satellite; an acceleration sensor for observing motion acceleration of the mobile object and gravity acceleration; altitude difference calculation means for calculating an altitude difference of road based on an atmospheric pressure value supplied from a barometric sensor; inclination calculation means for calculating an inclination angle of the road in the direction of the motion, based on the altitude difference and a travel distance corresponding to the mobile object's speed; and attachment angle calculation means for calculating an attachment angle of the acceleration sensor with respect to the mobile object by using a multidimensional function formula including the acceleration in the direction of motion, the lateral acceleration, values observed by the acceleration sensor and the inclination angle, the observed values including the motion acceleration and the gravity acceleration.