V. V. Krizhanovskii, V. V. Krizhanovskii (jr.) A potential efficiency of non-invasive estimating of acoustic parameters of artifacts of the respiratory tract |
Acoustic bulletin, Vol. 13 ¹ 1, (2010) |
| A problem on estimating of acoustic parameters of local artifacts of the objects is investigated using the statistical approach. The estimation variance and its shift are used for the informative statistical characteristics determining the accuracy of estimation. The dependence of the referred estimation errors from signal-to-noise ratio has been considered. On the basis of matrices of cross-spectral power densities for the signals recorded in given system of points, the dependencies of estimation variance from frequency range, degree of signal sectioning, number of receivers in the antenna and their arrangement have been theoretically analyzed. The estimation effectiveness has been studied as a function of the degree of coherence of acoustic signal sources, its spatial distribution and sizes of the artifacts. The effect of antenna's location with respect to signal source, artifact and boundaries of objects on estimation accuracy has been considered. On the basis of the earlier developed canonical models for artifacts of the cylindrical pipe's wall, the influence of specified factors on estimation variance of sound velocity in artifact's domain and position of maximum of sensitivity function, that describes the error shifts of mentioned estimate, has been quantitatively analyzed. The effective layouts of a limited number of receivers in antennas have been determined for some typical situations. |
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KEY WORDS: an object’s artifact, multielement antenna, sensitivity function, signal-to-noise ratio, error shift |
| TEXT LANGUAGE: Russian |