Estimating Q from VSP data: Comparing spectral ratio and analytical signal methods
Arnim B. Haase, Robert R. Stewart
Most of our Q-estimation investigations in previous work are based on the analytical signal method. Surprisingly large Q-factors at shallow depths had been observed for a Ross Lake VSP. In this report we are comparing the analytical signal approach to the spectral ratio method for two different VSP data sets. The two Q-estimation methods compare well when equal depth intervals are chosen for the analysis. Stratigraphic (apparent) Q appears to dominate the estimated "Q versus depth" functions in both VSP locations.