Gabor Domain Analysis of Q in the Near-surface

We present a Q estimation method where analysis is done in the Gabor domain. There, attenuation is estimated as a function of frequency (f), and Q (f) is computed through inversion of attenuation. We provide an example based on a 7-level, near-offset VSP consisting of 3-component receivers and sweeps. Eight, narrowband sweeps are used to span 10 Hz - 250 Hz for each source orientation. Two subunits are identified within the local formation that correspond to an expected 50 m of unsaturated media underlain by an aquifer. Our results demonstrate that attenuation varies near-linearly with frequency for the 95 m depth range. Strong values of attenuation that increase with frequency are found in the unsaturated unit, and weaker, decreasing attenuation is found in the saturated unit.