| 摘要 |
<P>PROBLEM TO BE SOLVED: To improve time-difference direction finding by accurately determining a frequency gradient (group delay time) of a phase component of a cross spectrum by increasing an effective band width by autonomous frequency dispersion of received signals. Ž<P>SOLUTION: A direction finder includes: first and second receiving antennas (1) arranged at a prescribed distance from each other for receiving incoming radio waves; a frequency dispersion part (3) for frequency dispersion of each frequency band of first and second received signals received by the first and second receiving antennas; a cross spectrum computing unit for computing the cross spectra of frequency-dispersed first and second received signals output from the frequency dispersion part; a time-difference detector (5) for detecting the time difference between incoming radio waves received by the first and second receiving antennas on the basis of a frequency gradient to the frequency of a phase in a frequency band having a high coherence level indicated by the cross spectra; and a direction computing unit (6) for computing the incoming direction of radio waves on the basis of the time difference and the prescribed distance. Ž<P>COPYRIGHT: (C)2010,JPO&INPIT Ž
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