Precise source location of AE doublets by spectral matrix analysis of triaxial hodogram

A precise relative source location technique has been developed using acoustic emission doublets (AE doublets) in the triaxial hodogram method to evaluate the direction and distance of subsurface extension cracks. An AE doublet is a pair of acoustic emissions with similar waveforms and adjacent locations on the same crack but which occur at different times. The relative source location is estimated by an analysis in the frequency domain. The relative distance between two AE sources is determined from the difference of P-S arrival time delays by cross-spectrum analysis. The relative direction is derived using a spectral matrix from the difference in P-wave polarization directions. The accuracy of the estimated source location was confirmed by performing field experiments. -from Authors