ORIENTATION CALCULATION APPARATUS, ORIENTATION CALCULATION METHOD, IMAGING APPARATUS INCLUDING ORIENTATION CALCULATION APPARATUS, AND METHOD FOR CONTROLLING SAME

An orientation calculation apparatus includes one or more processors and one or more memories that are configured to obtain detection signals from a first and a second sensor configured to detect the movement of the moving apparatus; calculate, as a first calculation, first orientation information about the moving apparatus; calculate, as a second calculation, second orientation information about the moving apparatus; determine which calculation to calculate an orientation of the moving apparatus is used as a determination; and update the reference angle. The reference angle is updated in synchronization with a timing when the one or more processors and the one or more memories determine that a state where the determination is to be switched from a state where the orientation of the moving apparatus is calculated using the second calculation to a state where the orientation is calculated using the first calculation.