Analysis of non-stationary mode coupling by means of wavelet-bicoherence

We present a definition of wavelet bicoherence based on wavelet polyspectra. We propose a simple estimator for wavelet bicoherence, and discuss its statistical properties. In particular it is shown that wavelet bicoherence estimation has a larger number of effective degrees of freedom than traditional Fourier-based bicoherence estimation. The proposed estimator is applied to detection of coherent couplings in rocket measurements from the ionospheric E-region. It is concluded that wavelet bicoherence is a tool well-suited for analysis of non-stationary mode coupling.

[1]  Alfred Hanssen,et al.  Multitaper estimators for bispectra , 1999, Proceedings of the IEEE Signal Processing Workshop on Higher-Order Statistics. SPW-HOS '99.

[2]  Alfred Hanssen,et al.  Wavelet-polyspectra: analysis of non-stationary and non-Gaussian/non-linear signals , 2000, Proceedings of the Tenth IEEE Workshop on Statistical Signal and Array Processing (Cat. No.00TH8496).

[3]  T. Dudok de Wit,et al.  Wavelet bicoherence analysis of strong plasma turbulence at the Earth`s quasiparallel bow shock , 1995 .

[4]  Edward J. Powers,et al.  The statistics of wavelet-based bicoherence , 1998, Proceedings of the IEEE-SP International Symposium on Time-Frequency and Time-Scale Analysis (Cat. No.98TH8380).

[5]  S. Mallat.  A wavelet tour of signal processing , 1998 .

[6]  S. Elgar,et al.  Statistics of bicoherence and biphase , 1989 .

[7]  Benjamin A. Carreras,et al.  Wavelet bicoherence: A new turbulence analysis tool , 1995 .

[8]  M.R. Raghuveer,et al.  Bispectrum estimation: A digital signal processing framework , 1987, Proceedings of the IEEE.

[9]  P. Laguna,et al.  Signal Processing , 2002, Yearbook of Medical Informatics.

[10]  E. Powers,et al.  Digital Bispectral Analysis and Its Applications to Nonlinear Wave Interactions , 1979, IEEE Transactions on Plasma Science.

[11]  Spectral properties of low-frequency electrostatic waves in the ionospheric E region , 2000 .