An Introduction to Surface Wave Analysis Michael E. Pasyanos - IRIS

Seismic Tomography
Tomography is an imaging method widely used in seismology for the
derivation of bulk earth properties such as velocity and attenuation from
measured properties along paths.
It is analogous to tomography methods used in medical imaging, such as
CT scans, but generally with much poorer coverage of the study region.
t = A x
We use it to invert dispersion measurements for spatially varying dispersion
values.
There are many methods to solve the inversion. We will be using a
program that uses the conjugate gradient method.