V.V.Krizhanovskii, V.V.Krizhanovskii (jr.) Studying the efficiency of non-invasive sound speed estimation in bounded objects with the inhomogeneities at linearization of data on phase delays |
Acoustic bulletin, Vol. 15 ¹ 2, (2012) |
| The paper deals with a problem of estimating of sound speed in bounded objects with the acoustic inhomogeneities comparable with the wavelength. The data on frequency dependence of phase delay of the signals received from a localized source in two reception points which coordinates are assumed to be known are used as the informative characteristics. On the basis of linearization of this frequency dependence, the algorithms for estimating of sound speed are developed and model studies of their efficiency are conducted for heterogeneous walls of the finite cylindrical pipe. The estimation errors for sound speed are analyzed depending on relative arrangement of the signal source, reception points and boundaries of the object at different wavelengths. The rational frequency parameters of estimation procedures and schemes of receivers arrangement are determined. For two variants of measurement set-up, the effect of the characteristic irregularities of the structures on the results is investigated. The efficiency of the proposed algorithm is confirmed experimentally on the example of estimating of sound speed in the lung parenchyma. |
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KEY WORDS: sound speed, estimation of parameters, the functional of the maximum likelihood, the relative error, parenchyma |
| TEXT LANGUAGE: Russian |