PURPOSE: To reduce a processing load on a computer which analyzes each of pulse data being data on a plurality of radar signals received simultaneously and detects the pulse data, and to enable detection of an increased number of aimed radar signals within a prescribed time.

CONSTITUTION: The frequency distribution 8 of azimuth and the frequency distribution 9 of a frequency are prepared for pulse data being data on a plurality of radar signals received simultaneously, while an azimuth classification number 11 showing a prescribed azimuth width of the frequency distribution 8 of the azimuth to which the said pulse data belong and a frequency classification number 12 showing a prescribed frequency width of the frequency distribution 9 of the frequency to which the data belong are added as the radar data on the occasion when the pulse data are accumulated respectively in the sequence of arrival.