Wave-equation migration Q analysis (WEMQA)

Q model building, which is conventionally done in the data space using ray-based tomography, is notoriously challenging due to issues such as spectral interference, low signal-to-noise ratio, diffractions, and complex subsurface structure. To produce a reliable Q model, we present a new approach with two major features. First, this method is performed in the imagespace, which uses downward-continuation imaging with Q to stack out noise, focus and simplify events, and provide a direct link between the model perturbation and the image perturbation. Second, this method uses wave-equation Q tomography to handle complex wave propagation. We apply this method to four 2D synthetic examples. The numerical synthetic test with a single reflector shows the capability of the downwardcontinuation imaging with Q to accurately migrate data in media with attenuation. Three numerical tests of this Q estimation method demonstrate its feasibility on the model with Q anomalies.