Application of several time-frequency analysis methods to the spectral analysis of rock fracture signals

Abstract

From a signal processing perspective, the acoustic emission and electromagnetic signals emitted by rocks are non-stationary signals. The Fourier transform, which is commonly used for spectrum analysis, is not suitable for analyzing such signals. To address this problem, we used various time-frequency analysis techniques, such as the short-time Fourier transform, continuous wavelet transform, generalized S transform, and Hilbert-Huang transform (HHT). It was found that HHT provides more accurate time-frequency information and reflects a better frequency aggregation effect comparing to the other methods for analyzing such signals