The position and orientation of a target object is obtained based on first measurement data obtained by a first sensor (first calculation). The position and orientation of the target object is obtained based on second measurement data obtained by a movable second sensor set in a position and orientation different from that of the first sensor (second calculation). When the position and orientation obtained by the first calculation and that obtained by the second calculation match each other, the position and orientation obtained by the first or second calculation or a position and orientation calculated from the position and orientation obtained by the first calculation and that obtained by the second calculation is output as the position and orientation of the target object.