ESTIMATION OF LOCATIONS AND STRENGTHS OF BROAD-BAND PLANAR AND SPHERICAL NOISE SOURCES USING COHERENT SIGNAL SUBSPACE

This paper presents the estimation methods of the planar and spherical wave sources with broadband frequency by using two types of coherent signal-subspace processing; one uses frequency correction of the unwrapped phase of the measured sound pressures at the microphone array in space domain, and the other uses the focusing procedures by using the focusing matrix. The simulations show that the method based on frequency correction has a rather simple procedure compared to that of the methods based on focusing procedures. The performances of these methods have been also investigated in terms of the frequency band, and the distance between sources. The MUSIC power spectrum by the former gives broader peaks than that of the latter but the latter makes some spurious peaks in the MUSIC power spectrum when the bearing angle between the sources and/or the frequency band of interest increases, provided that one assumes a planar wave field. For the spherical wave field, these phenomena were less sensitive than those of the planar wave held. (C) 1995 Acoustical Society of America.