RADAR SIGNAL PROCESSING DEVICE, RADAR SIGNAL PROCESSING METHOD, RADAR DEVICE, AND IN-VEHICLE DEVICE

A radar signal processing device includes processing circuitry configured to repeatedly acquire a beat signal having a frequency of a difference between a frequency of a radar signal and a frequency of a reflected wave of the radar signal reflected by an observation target, repeatedly calculate a distance between a radar device and the observation target using the acquired beat signal, and repeatedly calculate a relative speed between the radar device and the observation target using the acquired beat signal; calculate an incident angle of the reflected wave to an array antenna by using the acquired beat signal and an arrangement interval between a plurality of reception antennas included in the array antenna; and determine whether the observation target is a detection target or a non-detection target due to electromagnetic noise based on the calculated incident angle, the plurality of distances and the plurality of relative speeds.