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Green function retrieval versus Interferometric imaging Kees Wapenaar Deyan Draganov Delft University of Technology 2005 Joint Assembly May 25, 2005 New Orleans. Contents. Green’s function retrieval Interferometric imaging Comparison. (passive) data. Contents.
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Green function retrieval versus Interferometric imaging Kees Wapenaar Deyan Draganov Delft University of Technology 2005 Joint Assembly May 25, 2005 New Orleans
Contents Green’s function retrieval Interferometric imaging Comparison
Contents Green’s function retrieval Interferometric imaging Comparison
1500 m/s 2000 m/s Retrieval of reflection response: acoustic approximation
(variable ) (fixed , variable )
(fixed , variable ) (fixed , variable )
1500 m/s 2000 m/s Uncorrelated noise sources
(fixed , variable ) (variable )
Contents Green’s function retrieval Interferometric imaging Comparison
(passive) data (passive) data
0 t • Forward extrapolation of ‘source’ • Inverse extrapolation of receiver • Cross-correlation • Integrate along receivers
Ghost • Forward extrapolation of ‘source’ • Inverse extrapolation of receiver • Cross-correlation • Integrate along receivers • Repeat for all subsurface points
Ghost Schuster, EAGE 2001, GJI 2004 Artman et al., EAGE 2004 Draganov et al., SEG 2004
Contents Green’s function retrieval Interferometric imaging Comparison
1500 m/s 2000 m/s Retrieval of reflection response: acoustic approximation Green’s function retrieval Integration along sources
Green’s function retrieval Integration along sources Interferometric imaging
Ghost Green’s function retrieval Integration along sources Interferometric imaging Integration along receivers
Green’s function retrieval Integration along sources Interferometric imaging Integration along receivers
Passive Seismic Imaging in Complex Media Numerical comparison with varying number of underground sources Reconstructed depth image Reconstructed reflection response Directly modelled reflection response 33 minutes of white noise recording with 225 subsurface sources
Passive Seismic Imaging in Complex Media Numerical comparison with varying number of underground sources Reconstructed depth image Reconstructed reflection response Directly modelled reflection response 6 minutes of white noise recording with 113 subsurface sources
Passive Seismic Imaging in Complex Media Numerical comparison with varying number of underground sources Reconstructed depth image Reconstructed reflection response Directly modelled reflection response 6 minutes of white noise recording with 57 subsurface sources
Passive Seismic Imaging in Complex Media Numerical comparison with varying number of underground sources Reconstructed depth image Reconstructed reflection response Directly modelled reflection response 6 minutes of white noise recording with 11 subsurface sources
Passive Seismic Imaging in Complex Media Numerical comparison with varying number of underground sources Reconstructed depth image Reconstructed reflection response Directly modelled reflection response 6 minutes of white noise recording with 6 subsurface sources
Conclusions • Green’s function retrieval • diffuse wave fields • non-diffuse wave fields: representation theory • many sources required • primaries and multiples (coda) • no medium information required • Interferometric imaging • diffuse ornon-diffuse wave fields • few sources required • primaries only (multiples imaged as ghosts) • background medium required