In Chapter~\ref{chap:field2}, I apply tau tomography
with steering filter regularization  to a 2-D line taken from
a 3-D  dataset acquired
over a salt-dome the North Sea.  The resulting migration image is better
focused with better resolution of the sediments on the salt flanks.
The final velocity model still shows velocity generally following  structure
rather than the blobby  nature common with other regularization techniques.
In Chapter~\ref{chap:field3d} I apply my method in 3-D.
I use the 
North Sea dataset introduced in Chapter~\ref{chap:field2},  concentrating
on the structure above the salt-dome, and improve both
focusing and resolution of the migrated image.
