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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.
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6 months at CWP: Done a lot, but not done yetOr: how to deal with black magicbyDr. Ernst NiederleithingerSenior Scientist and Deputy Division Leader atBAM( Federal Institute for Materials Research and Testing)Berlin, GermanyVisiting Research Professor at Colorado School of Mines CWP Seminar, 2013-12-02 Niederleithinger 1
Motivation to come here: But there was morethanthat! CWP Seminar, 2013-12-02 Niederleithinger 2
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
Events • Seismics: Earthquakes, fracking,…. • Concrete: Load induced cracks,… • Localization, Characterization CWP Seminar, 2013-12-02 Niederleithinger 4
Events • Onetool: Time Reversal (Fink et al.) • Reciprocity • Inject time reversedsignalsatreceivers • Energy will focusatsource CWP Seminar, 2013-12-02 Niederleithinger 5
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
Does it really work? Experiment! CWP Seminar, 2013-12-02 Niederleithinger 7
Does it really work? Experiment! CWP Seminar, 2013-12-02 Niederleithinger 8
Setup: forward CWP Seminar, 2013-12-02 Niederleithinger 9
Data: forward CWP Seminar, 2013-12-02 Niederleithinger 10
Setup: backwards CWP Seminar, 2013-12-02 Niederleithinger 11
Data: backward CWP Seminar, 2013-12-02 Niederleithinger 12
Focus! CWP Seminar, 2013-12-02 Niederleithinger 13
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
Simple experiments: subtle changes detected,but no localization! CWP Seminar, 2013-12-02 Niederleithinger 15
Localization is possible! CWP Seminar, 2013-12-02 Niederleithinger 16
Don’t believe it? Experiment! CWP Seminar, 2013-12-02 Niederleithinger 17
Don’t believe it? Experiment! CWP Seminar, 2013-12-02 Niederleithinger 18
Don’t believe it? Experiment! CWP Seminar, 2013-12-02 Niederleithinger 19
Results (“simple” CWI) CWP Seminar, 2013-12-02 Niederleithinger 20
Results (“simple” CWI) CWP Seminar, 2013-12-02 Niederleithinger 21
Preliminary Results (“advanced” CWI) CWP Seminar, 2013-12-02 Niederleithinger 22
Preliminary Results (“advanced” CWI) CWP Seminar, 2013-12-02 Niederleithinger 23
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
RTM Ultrasonic black magic in TV CWP Seminar, 2013-12-02 Niederleithinger 25
SAFT imaging 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) Main contributors to SAFT: Langenberg, Mayer, Marklein, University of Kassel CWP Seminar, 2013-12-02 Niederleithinger 26
Reverse Time Migration! Sabine Müller Ernst Niederleithinger Maria Grohmann Martin Krause Thomas Bohlen Paul Sava CWP Seminar, 2013-12-02 Niederleithinger 27
RTM Synthetic example 1 Model used for simulating data Velocity modelfor migration RTM result CWP Seminar, 2013-12-02 Niederleithinger 28
Off to Horstwalde Foundation slab at our test site CWP Seminar, 2013-12-02 Niederleithinger 29
Off to Horstwalde CWP Seminar, 2013-12-02 Niederleithinger 30
Off to Horstwalde CWP Seminar, 2013-12-02 Niederleithinger 31
Off to Horstwalde Simulations CWP Seminar, 2013-12-02 Niederleithinger 32
Off to Horstwalde Real data CWP Seminar, 2013-12-02 Niederleithinger 33
Back to the lab • Measurements: • Polyamide block,(100*60*30 cm³) • Point contact transducersin arrays of 4 • P, SHx, SHy CWP Seminar, 2013-12-02 Niederleithinger 34
Back to the lab CWP Seminar, 2013-12-02 Niederleithinger 35
Back to the lab CWP Seminar, 2013-12-02 Niederleithinger 36
Seismic Interferometry 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
Seismic Interferometry „Green‘s function retrieval“, „Seismic Interferometry“ Trace interpolation, synthetic example (44 sources) CWP Seminar, 2013-12-02 Niederleithinger 38
Seismic Interferometry „Green‘s function retrieval“, „Seismic Interferometry“ Trace interpolation, synthetic example (44 sources) CWP Seminar, 2013-12-02 Niederleithinger 39
Seismic Interferometry „Virtual Real Source“ (Behura, 2006) synthetic example (11 sources) CWP Seminar, 2013-12-02 Niederleithinger 40
Back to the lab Just more black magic? Experiment! (on the way) CWP Seminar, 2013-12-02 Niederleithinger 41
That will be simple. Reality is much more complicated: CWP Seminar, 2013-12-02 Niederleithinger 42
Let‘s steal anotherblack magic idea: Autofocusing CWP Seminar, 2013-12-02 Niederleithinger 43
Let‘s steal anotherblack magic idea: Autofocusing CWP Seminar, 2013-12-02 Niederleithinger 44