Abstract
Noise rejection is of primordial importance in Thermoelasticimetry. The evaluation of stresses by means of the thermoelastic effect requires high accuracy measurement of the dynamic temperature changes of a sample under cyclic mechanical loading. One has chosen a statistical method to reject the noise of sinusoidal signals (quite important for a standard infrared camera (0,05 K)) and to estimate their amplitudes. Digital treatment of a series of thermographic images allows for the calculation of the temporal distribution of every pixel.
Without loading, these distributions are similar to the Gaussian distribution of a white noise. Under cyclical loading one obtains the distribution of the sum of sinusoidal signal and white noise. Therefore this distribution is wider than the Gaussian one. Its width is a function of the signal amplitude. Thus, comparing both distributions, it is possible to estimate the amplitude of the cyclic signal.
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© 1994 Springer Science+Business Media Dordrecht
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Offermann, S., Merienne, E., Beaudoin, J.L. (1994). Statistical Method to Evaluate the Amplitude of Cyclical Noisy Signal in IR Thermography. In: Maldague, X.P.V. (eds) Advances in Signal Processing for Nondestructive Evaluation of Materials. NATO ASI Series, vol 262. Springer, Dordrecht. https://doi.org/10.1007/978-94-011-1056-3_4
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DOI: https://doi.org/10.1007/978-94-011-1056-3_4
Publisher Name: Springer, Dordrecht
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