1. A radar apparatus, comprising: a clutter analysis unit configured to analyze a clutter value of a signal that is received by a reception unit; a screen change detection unit configured to calculate a screen change time up to a time at which a screen has been changed from an image captured by an imaging apparatus; a representative value acquisition unit configured to acquire a representative value based on a plurality of clutter values analyzed for the screen change time by the clutter analysis unit; and a target detection unit configured to determine the signal to be a target signal if a size of the signal is larger than both the clutter value and representative value of the signal.