Frequency-domain autocorrelation imaging condition for 3D elastic time-reversal imaging

초록

In this study, we propose a frequency-domain autocorrelation as an imaging condition for time-reversal imaging. The previous imaging conditions in time-reversal imaging require time-domain calculations such as inverse Fourier transform. The computational burden of these calculations is critical; therefore, time-reversal imaging is not the proper method for real-time event localization. We exclude these time-domain calculations for efficiency. Instead, the maximum amplitude position of the frequency-domain autocorrelation of the time-reversal wavefield is determined as a source location. We conducted numerical tests to validate our imaging condition. The synthetic data test shows that our proposed algorithm provides a more credible source localization result than the conventional grid-search method does in a noisy environment even using only one frequency component with many receivers. We also applied our algorithm to two real datasets acquired from the small monitoring network in Pohang. The real-data test shows a comparable result with the result of the grid-search method.

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