An information processing apparatus comprising: first calculation means for calculating a first calculated position and orientation of a target object based on first measurement data obtained by a fixed sensor located at a first position and orientation; second calculation means for calculating a second calculated position and orientation of the target object based on second measurement data obtained by a movable sensor moved to a second position and orientation different from the first position and orientation; determination means for determining whether the first calculated position and orientation calculated by said first calculation means and the second calculated position and orientation calculated by said second calculation means match; output means for, if said determination means determines that the first calculated position and orientation and the second calculated position and orientation match each other, outputting, a position and orientation of the target object based on at least one of the first calculated position and orientation and the second calculated position and orientation; and execution control means for, if said determination means determines that the first calculated position and orientation and the second calculated position and orientation do not match each other, controlling means for moving the moveable sensor to change the position and orientation of the moveable sensor from the second position and orientation to a third position and orientation and upon moving the moveable sensor executing again the calculation by said second calculation means and the determination by said determination means. first calculation means for calculating a first calculated position and orientation of a target object based on first measurement data obtained by a fixed sensor located at a first position and orientation; second calculation means for calculating a second calculated position and orientation of the target object based on second measurement data obtained by a movable sensor moved to a second position and orientation different from the first position and orientation; determination means for determining whether the first calculated position and orientation calculated by said first calculation means and the second calculated position and orientation calculated by said second calculation means match; output means for, if said determination means determines that the first calculated position and orientation and the second calculated position and orientation match each other, outputting, a position and orientation of the target object based on at least one of the first calculated position and orientation and the second calculated position and orientation; and execution control means for, if said determination means determines that the first calculated position and orientation and the second calculated position and orientation do not match each other, controlling means for moving the moveable sensor to change the position and orientation of the moveable sensor from the second position and orientation to a third position and orientation and upon moving the moveable sensor executing again the calculation by said second calculation means and the determination by said determination means.