I have presented a regularized least-squares inversion scheme to image the reflectivity.
This inversion scheme allows us to perform inversion in a target-oriented fashion, and the total cost is about two migrations
(one for computing the migrated image, the other for computing the phase-encoded Hessian). Examples on the Marmousi model
show that regularization that promotes sparsity
in the image domain help to reduce the null space and to mitigate the effects of operator mismatch. Inversion with the sparseness
constraint can lead to a better solution with higher resolution than that regularized with the standard -norm damping.