P-Wave Onset Detection Based on the Spectrograms of the AE Signals
Determining the onset of acoustic emissions (AE) signal is very time consuming if the onset is picked manually, so it is important to read the arrival times of P phase automatically. Automatic onset detection and picking algorithm has been proposed by applying the spectro-ratio on time–frequency sub-band. Powers of frequency sub-bands are determined by spectrogram as a time–frequency representation. Adaptive thresholds are calculated for one of these sub-bands to check if there is a P-wave arrival in the segment or not. To verify this check another test is done using the spectro-ratio. The application of this algorithm on the AE signals from the pencil-breaking test shows a reasonable result.
Guangfan Li, Yong Huang and Chaohe Chen
J. Xu "P-Wave Onset Detection Based on the Spectrograms of the AE Signals", Advanced Materials Research, Vols. 250-253, pp. 3807-3810, 2011