On the accuracy of the power spectrum estimate in the directive spectrum analyzing system by use of a moving microphone.
Masato Abe, Masaaki Ishigame, Ken’iti Kido · Journal of the Acoustical Society of Japan (E) · 1980
This paper describes two methods of increasing the accuracy of the power spectrum estimate in the directive spectrum analyzing system by use of a moving microphone. The objective of the system is to estimate the power spectrum radiated from a specified sound source when there are some other sources. The system is composed of two microphones, one of which is fixed and the other moves along a straight line from the fixed microphone to the sound source. By giving adequate delay to the output of the moving microphone, the system estimates the power spectrum of the sound from the direction of the sound source, eliminating the effects of sounds from other directions. First, this paper presents a method of giving the delay in the frequency domain instead of the time domain, by which the accurate delay is given to the output of the moving microphone. Secondly, this paper presents a method of suppressing the side lobes with an adequate spatial weighting, by which the errors due to the sounds from other directions are decreased.