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Instantaneous frequency and amplitude identification using wavelets: Application to glass structure

J. D. Harrop·S. N. Taraskin·S. R. Elliott
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Abstract

This paper describes a method for extracting rapidly varying, superimposed amplitude- and frequency-modulated signal components. The method is based upon the continuous wavelet transform (CWT) and uses a new wavelet which is a modification to the well-known Morlet wavelet to allow analysis at high resolution. In order to interpret the CWT of a signal correctly, an approximate analytic expression for the CWT of an oscillatory signal is examined via a stationary-phase approximation. This analysis is specialized for the new wavelet and the results are used to construct expressions for the amplitude and frequency modulations of the components in a signal from the transform of the signal. The method is tested on a representative, variable-frequency signal as an example before being applied to a function of interest in our subject area - a structural correlation function of a disordered material - which immediately reveals previously undetected features.

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J. D. Harrop, S. N. Taraskin, S. R. Elliott. 2002-02-15. Instantaneous frequency and amplitude identification using wavelets: Application to glass structure. https://doi.org/10.1103/physreve.66.026703

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