Least-squares AVF inversion for Q extraction

This paper gets the Q through the AVF inversion which uses the new frequency dependent absorptive reflectivity linearization and the least-squares method. The new linear formula expands the suggest that elastic overburden overlays a high attenuation target to those that any (elastic or attenuate) overburden overlays a high attenuation target. So the new linear formula makes the expression more reasonable and more universal. Besides that, AVF inversion is unstable because of wavelet and noise. So we develop a method here of casting the AVF inverse problem as a leastsquares minimization problem. The results show that leastsquares AVF inversion can get exact and stable Q.