In this article, three methods of Q estimation are compared: a complex spectral ratio method, the centroid frequency-shift method, and a time-domain match-filter method. Their performance for Q estimation is evaluated using synthetic data and real data in terms of accuracy and robustness to noise. Testing results shows that the complex spectral-ratio method, with phase information employed, can obtain improved estimation results. The centroid frequency-shift method is robust to noise and gives stable estimations, while the accuracy of estimated result is subject to the frequency band used to estimate centroid frequency and variance. The match-filter method is robust to noise and can give accurate estimation result for both VSP data and reflection data.
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