Patent attributes
A dual-frequency CW processing unit (12) calculates an observation-point orientation of an observation point. An FMCW processing unit (11) calculates at least a power spectrum of a beat signal, which has been generated based on radar waves that have come from the calculated observation-point orientation, in terms of an up-modulation time interval and a down-modulation time interval (termed orientation power spectrum hereinafter). The FMCW processing unit (11) shifts the orientation power spectra of the up- and down-modulation time intervals to positive and negative directions, respectively, by an amount corresponding to a Doppler shift frequency. The FMCW processing unit (11) calculates a differential power spectrum by differentiating the orientation power spectra of the shifted up- and down-modulation time intervals, and detects a peak frequency where intensity is maximum.
