There are provided an object distinguishing unit that distinguishes an object every predetermined calculation cycle; and a state determination unit that determines a relative state between the object distinguished by the object distinguishing unit and a vehicle and that performs switching control in which based on the result of the determination, there is performed switching from one of a first angle detection unit and a second angle detection unit to the other in the next calculation cycle, and the value of an incident angle is inputted to the object distinguishing unit.