Penalty terms in the truncated Newton inner-loop for full-waveform inversion

Scott Keating, Kristopher A. Innanen

Inter-parameter cross-talk, where physical properties are confused with one another, is a major concern in multi-parameter full waveform inversion. Cross-talk is difficult to prevent, not least because it is difficult to identify in a recovered model. Certain modes of cross-talk, however, may be more evident in the model updates used in the inversion. We propose penalizing evidence of cross-talk in the model updates within a truncated Newton optimization. We test this approach to penalize cross-talk between vP and QP in a viscoelastic inversion. We find that an update penalty term can be effectively included in a truncated Newton strategy, but that the penalty terms we investigate are poor measures of cross-talk.