Acknowledgements

Thanks to discussions with Bob Clapp and James Rickett, I gained many valuable insights on theoretical and practical issues pertaining to this paper. Jon Claerbout and Sergey Fomel developed and presented many of the recent advances in SEP's methods of practical inversion. Biondo Biondi and Matthias Schwab independently suggested that I approach this problem in terms of anisotropy. Chevron Overseas Petroleum donated the data shown herein.