1. 6 months at CWP: Done a lot, but not done yet Or: how to deal with black magic by Dr. Ernst Niederleithinger Senior Scientist and Deputy Division Leader at BAM( Federal Institute for Materials Research and Testing) Berlin, Germany Visiting Research Professor at Colorado School of Mines CWP Seminar, 2013-12-02 Niederleithinger 1

2. Motivation to come here: But there was more than that! CWP Seminar, 2013-12-02 Niederleithinger 2

3. Content Things to be cared about in geophysics and NDT: Events Changes Images Where to go from here? CWP Seminar, 2013-12-02 Niederleithinger 3

4. Events Seismics: Earthquakes, fracking,…. Concrete: Load induced cracks,… Localization, Characterization CWP Seminar, 2013-12-02 Niederleithinger 4

5. Events One tool: Time Reversal (Fink et al.) Reciprocity Inject time reversed signals at receivers Energy will focus at source CWP Seminar, 2013-12-02 Niederleithinger 5

6. Events One tool: Time Reversal (Fink et al.) Reciprocity Inject time reversed signals at receivers Energy will focus at source Improvement? Deconvolution! CWP Seminar, 2013-12-02 Niederleithinger 6

7. Does it really work? Experiment! CWP Seminar, 2013-12-02 Niederleithinger 7

8. Does it really work? Experiment! CWP Seminar, 2013-12-02 Niederleithinger 8

9. Setup: forward CWP Seminar, 2013-12-02 Niederleithinger 9

10. Data: forward CWP Seminar, 2013-12-02 Niederleithinger 10

11. Setup: backwards CWP Seminar, 2013-12-02 Niederleithinger 11

12. Data: backward CWP Seminar, 2013-12-02 Niederleithinger 12

13. Focus! CWP Seminar, 2013-12-02 Niederleithinger 13

14. Next topic: Changes Seismics: stress, oil/gas content,…. Concrete: stress, degradation,…. Both: Detect it as early as possible! „Global“ changes: Coda Wave Interferometry Localization? Ideas by Pacheco & Snieder, Larose, Sens-Schönfelder,…. CWP Seminar, 2013-12-02 Niederleithinger 14

15. Simple experiments: subtle changes detected, but no localization! CWP Seminar, 2013-12-02 Niederleithinger 15

16. Localization is possible! CWP Seminar, 2013-12-02 Niederleithinger 16

17. Don’t believe it? Experiment! CWP Seminar, 2013-12-02 Niederleithinger 17

18. Don’t believe it? Experiment! CWP Seminar, 2013-12-02 Niederleithinger 18

19. Don’t believe it? Experiment! CWP Seminar, 2013-12-02 Niederleithinger 19

20. Results (“simple” CWI) CWP Seminar, 2013-12-02 Niederleithinger 20

21. Results (“simple” CWI) CWP Seminar, 2013-12-02 Niederleithinger 21

22. Preliminary Results (“advanced” CWI) CWP Seminar, 2013-12-02 Niederleithinger 22

23. Preliminary Results (“advanced” CWI) CWP Seminar, 2013-12-02 Niederleithinger 23

24. Last but not least: Imaging Seismics: Layers, structures, hydrocarbons Concrete: rebars, tendons, voids, cracks,… Both: Mapping (multiple) reflections recorded close to/at the surface to where they belong! Same math+physics! CWP Seminar, 2013-12-02 Niederleithinger 24

25. RTM Ultrasonic black magic in TV CWP Seminar, 2013-12-02 Niederleithinger 25

26. SAFT imaging Main contributors to SAFT: Langenberg, Mayer, Marklein, University of Kassel Friese et al., SMT 2008 Synthetic aperture focusing technique Family of methods Constant and multi-offset data Direct reflections only Phase evaluation possible (Krause et al., SF&R 2008) CWP Seminar, 2013-12-02 Niederleithinger 26

27. Reverse Time Migration! Sabine Müller Ernst Niederleithinger Maria Grohmann Martin Krause Thomas Bohlen Paul Sava CWP Seminar, 2013-12-02 Niederleithinger 27

28. Synthetic example 1 RTM Model used for simulating data Velocity model for migration RTM result CWP Seminar, 2013-12-02 Niederleithinger 28

29. Off to Horstwalde Foundation slab at our test site CWP Seminar, 2013-12-02 Niederleithinger 29

30. Off to Horstwalde CWP Seminar, 2013-12-02 Niederleithinger 30

31. Off to Horstwalde CWP Seminar, 2013-12-02 Niederleithinger 31

32. Off to Horstwalde Simulations CWP Seminar, 2013-12-02 Niederleithinger 32

33. Off to Horstwalde Real data CWP Seminar, 2013-12-02 Niederleithinger 33

34. Back to the lab Measurements: Polyamide block, (100*60*30 cm³) Point contact transducers in arrays of 4 P, SHx, SHy CWP Seminar, 2013-12-02 Niederleithinger 34

35. Back to the lab CWP Seminar, 2013-12-02 Niederleithinger 35

36. Back to the lab CWP Seminar, 2013-12-02 Niederleithinger 36

37. Seismic Interferometry Reconstruction of Greens functions Data, where you think you don‘t have data Gerald Schuster Roel Snieder Kees Wapenaar CWP Seminar, 2013-12-02 Niederleithinger 37

38. „Green‘s function retrieval“, „Seismic Interferometry“ Trace interpolation, synthetic example (44 sources) Seismic Interferometry CWP Seminar, 2013-12-02 Niederleithinger 38

39. „Green‘s function retrieval“, „Seismic Interferometry“ Trace interpolation, synthetic example (44 sources) Seismic Interferometry CWP Seminar, 2013-12-02 Niederleithinger 39

40. „Virtual Real Source“ (Behura, 2006) synthetic example (11 sources) Seismic Interferometry CWP Seminar, 2013-12-02 Niederleithinger 40

41. Back to the lab Just more black magic? Experiment! (on the way) CWP Seminar, 2013-12-02 Niederleithinger 41

42. That will be simple. Reality is much more complicated: CWP Seminar, 2013-12-02 Niederleithinger 42

43. Let‘s steal another black magic idea: Autofocusing CWP Seminar, 2013-12-02 Niederleithinger 43

44. Let‘s steal another black magic idea: Autofocusing CWP Seminar, 2013-12-02 Niederleithinger 44