Spectral Ratio Method for Q-Value Estimation in Seismic Exploration

Seismic exploration plays a vital role in subsurface investigation. To better understand underground conditions during exploration, various methods and tools are employed. The Spectral Ratio Method for Q-value estimation stands as a widely used technique that enhances the accuracy of subsurface characterization. This method determines the quality factor (Q) of underground media by analyzing the spectral ratio of seismic signals, which consequently helps infer subsurface structural information. The implementation typically involves comparing amplitude spectra from different depth levels using logarithmic difference calculations: Q = πΔt / ln(A1/A2) × (f2-f1), where A1 and A2 represent spectral amplitudes at frequencies f1 and f2 separated by time interval Δt. This approach offers simplicity in execution while maintaining high precision, making it extensively applied in seismic exploration workflows. Key processing steps include spectral decomposition using FFT, logarithmic transformation of amplitude ratios, and linear regression analysis to derive stable Q estimates across frequency bands.