Application of wavelet packet decomposition and its energy spectrum on the coal－rock interface identification＊

The theory and method of wavelet packet decomposition and its energy spectrum dealing with the coal-rock Interface Identification are presented in the paper. The characteris-tic frequency band of the coal-rock signal could be identified by wavelet packet decomposition and its energy spectrum conveniently, at the same time, quantification analysis were per-formed. The result demonstrates that this method is more advantageous and of practical val-ue than traditional Fourier analysis method.