DocumentCode :
2663849
Title :
Application of wavelet threshold de-noising to sound travel-time estimation
Author :
Yan, Hua ; Chen, Guannan ; Han, Junfeng ; Zhou, Yinggang
Author_Institution :
Sch. of Inf. Sci. & Eng., Shenyang Univ. of Technol., Shenyang, China
Volume :
1
fYear :
2010
fDate :
16-18 April 2010
Abstract :
The key to stored grain temperature measurement by acoustic method is to measure sound travel-time exactly. Grain is a highly absorbing acoustic medium, as a result, the sound signal received by the microphone far from the sound source has very low signal-to-noise ratio. In order to improve the sound travel-time estimation accuracy, a wavelet denoising-based cross correlation approach (in short CC_WTDN) is proposed. Soft threshold is used for its nice mathematical properties. Four threshold selection rules, that is, VisuShrink estimator, SUREShrink estimator, Heuristic estimator and Minimax estimator are tried. Simulation results based on a acoustic model of grain show that basic coross correlation method (BCC) can work well only when the sound wave path is not longer than 7.07m; while CC_WTDN can give good estimations even if the sound wave path is long as 10m. The four threshold rules tried give similar de-noising effects. The levels of wavelet decomposition have significant influence on de-noising effect.
Keywords :
acoustic correlation; acoustic variables measurement; minimax techniques; signal denoising; temperature measurement; time measurement; wavelet transforms; SUREShrink estimator; VisuShrink estimator; acoustic medium; acoustic method; basic crosscorrelation method; grain temperature measurement; heuristic estimator; microphone; minimax estimator; signal-to-noise ratio; sound signal; sound travel-time estimation; sound travel-time measurement; wavelet threshold denoising; Acoustic measurements; Acoustic signal detection; Acoustic waves; Atmospheric measurements; Discrete wavelet transforms; Noise reduction; Signal to noise ratio; Temperature measurement; Temperature sensors; Thermodynamics; acoustic temperature measurement; cross correlation; stored grain; time delay estimation; wavelet thresholding de-noising;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Computer Engineering and Technology (ICCET), 2010 2nd International Conference on
Conference_Location :
Chengdu
Print_ISBN :
978-1-4244-6347-3
Type :
conf
DOI :
10.1109/ICCET.2010.5486199
Filename :
5486199
Link To Document :
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