Stanford Exploration Project Passive Seismic Imaging Return to

Stanford Exploration Project Passive Seismic Imaging Return to Passive Imaging Brad Artman Spring 2002 SEP 111 page 359 brad@sep. stanford. edu 1

Stanford Exploration Project Passive Seismic Imaging State of Affairs Claerbout’s Conjecture Terra/Helio-seismology Exploration Engineering Success brad@sep. stanford. edu 2

Stanford Exploration Project • • Passive Seismic Imaging Passive Imaging Concepts 2 D Experiments Reformulation as Migration Path Forward brad@sep. stanford. edu 3

Stanford Exploration Project Passive Seismic Imaging Ambient Noise r 1 r 2 t a r 1*r 1 r 1*r 2 lag b brad@sep. stanford. edu c 4

Stanford Exploration Project • • Passive Seismic Imaging Passive Imaging Concepts 2 D Experiments Reformulation as Migration Path Forward brad@sep. stanford. edu 5

Stanford Exploration Project Passive Seismic Imaging The Sun as a Laboratory Acoustic Daylight Imaging via spectral factorization, Rickett SEP-100 brad@sep. stanford. edu 6

Stanford Exploration Project Passive Seismic Imaging 2 D Experiment 1 Receiver line brad@sep. stanford. edu 7

Stanford Exploration Project Passive Seismic Imaging Break Point? brad@sep. stanford. edu 8

Stanford Exploration Project Passive Seismic Imaging Whole Data Volume brad@sep. stanford. edu 9

Stanford Exploration Project Passive Seismic Imaging 8 Consecutive Lines brad@sep. stanford. edu 10

Stanford Exploration Project Passive Seismic Imaging 8 Spaced Lines brad@sep. stanford. edu 11

Stanford Exploration Project Passive Seismic Imaging 2 D Experiment brad@sep. stanford. edu 12

Stanford Exploration Project Passive Seismic Imaging 2+D Experiment brad@sep. stanford. edu 13

Stanford Exploration Project Passive Seismic Imaging 2. 5 D Experiment brad@sep. stanford. edu 14

Stanford Exploration Project • • Passive Seismic Imaging Passive Imaging Concepts 2 D Experiments Reformulation as Migration Path Forward brad@sep. stanford. edu 15

Stanford Exploration Project Passive Seismic Imaging Areal Source Wavefield Shot-profile migration of multiple reflections, Guitton, Tues. 11: 45 brad@sep. stanford. edu 16

Stanford Exploration Project Passive Seismic Imaging Shot-Profile Migration I(z, x)=Σ P (ω, x, s) ω s z g z Pz is the wave field at each depth level, where source and receiver fields are propagated independently via SSR. s g Realization: If P = P , correlation requirement of the passive seismic conjecture is fulfilled in the migration. Let the wave equation handle the unknown source. brad@sep. stanford. edu 17

Stanford Exploration Project Passive Seismic Imaging Synthetic Tests m s brad@sep. stanford. edu 18

Stanford Exploration Project Passive Seismic Imaging Two horizontal planes m m m brad@sep. stanford. edu 19

Stanford Exploration Project Passive Seismic Imaging Point Diffractor brad@sep. stanford. edu 20

Stanford Exploration Project Passive Seismic Imaging Synthetic Tests m s brad@sep. stanford. edu 21

Stanford Exploration Project Passive Seismic Imaging Crosscorrelation Technique Passive Seismic Imaging applied to synthetic data, Rickett SEP-92 brad@sep. stanford. edu 22

Stanford Exploration Project Passive Seismic Imaging Ambient Noise 2 r 1 r 2 t a r 1*r 1 r 1*r 2 lag b brad@sep. stanford. edu c 23

Stanford Exploration Project Passive Seismic Imaging Cost Comparison • Correlations 2 Nxy – Spatial increase: Nxy to – Temporal decrease: Nt to Nlag 2 – Migrate (S. P. ): Nxy N h xy Nlag Nz (+5 O. M. ) (- 4 O. M. ) • Skipping Correlations – No spatial or frequency change: Nxy , Nt – Migrate (S. P. ): Nxy N h xy Nt Nz brad@sep. stanford. edu 24

Stanford Exploration Project • • Passive Seismic Imaging Passive Imaging Concepts 2 D Experiments Reformulation as Migration Path Forward brad@sep. stanford. edu 25

Stanford Exploration Project Passive Seismic Imaging Plan of Attack • Data collection – May 2002, Ran Bachrach • Correlation scale • Surface velocity effects • Geophone arrays – Summer 2002, Western States tour? – Fall 2002, Spring 2003 • 3 D acquisition • Seismological data tests/ Code preparation brad@sep. stanford. edu 26

Stanford Exploration Project Passive Seismic Imaging Thank You brad@sep. stanford. edu 27