Application Study of Empirical Wavelet Transform in Time–Frequency Analysis of Electromagnetic Radiation Induced by Rock Fracture

The time–frequency characteristics of electromagnetic radiation (EMR) waveform induced by rock fracture are very important to the monitoring and early–warning using EMR method for mine rockburst. empirical wavelet transform (EWT), as a analysis method, has advantages clear theoretical basis, convenient calculation, no modal aliasing. To apply EWT field analysis, operation Fourier axis segmentation is improved. In detail, adaptive selection window width closing determination segment number proposed EWT. obtained short–time (STFT) used in process, rather than that discrete (DFT), taking better effect. improved together with Hilbert (HT) applied fracture, spectrum EWT–HT can well describe evolution characteristics. Compared STFT Hilbert–Huang (HHT), significant resolution overcoming aliasing, providing powerful tool fracture.