3D elastic time-frequency full-waveform inversion

In this work I present the theory and implementation of a 3D elastic full waveform inversion. The implementation is based on the adjoint-state method using a time-frequency approach. Synthetic applications in transmission acquisition geometry show the ability of the method to reconstruct elastic parameters of different 3D subsurface structures. Optimisations with the diagonal Hessian matrix for preconditioning and the L-BFGS scheme enable the inversion of more complex surface geometry data.