Discriminating physical and non-physical diffracted energy in source-receiver interferometry

作者：Meles Giovanni Angelo^*; Curtis Andrew

来源：Geophysical Journal International, 2014, 197(3): 1642-1659.

DOI：10.1093/gji/ggu054

• Interferometry
• Wave scattering and diffraction
• Wave propagation
• Acoustic properties

We show how physical and non-physical diffracted waves can be discriminated in source-receiver interferometry (SRI), a wavefield interferometric method that constructs Green's functions between any source-receiver pair. These can be estimated by convolution and cross-correlation of wavefields propagating to or from other sources or receivers. SRI has been observed to work surprisingly well in practical applications when theoretical requirements (e.g. complete enclosing boundaries of other sources and receivers) are contravened as is standard in practical applications. As a partial explanation to this, it has been demonstrated previously that SRI for single diffractor problems produces correct Green's functions estimates without requiring wavefields to be generated around specific stationary-phase points in space (as is required by other forms of interferometry). In this paper, we show that also for multiple-diffractor problems, any boundary source-receiver pair produces stationary, correct kinematics for singly and multiply diffracted waves. However, when multiple diffractors are present, non-physical artefacts are produced in Green's functions estimated by SRI with incomplete boundaries. We introduce a purely data-driven algorithm that allows traveltimes of any order of physical, diffracted waves to be predicted. This reduces ambiguity in interpreting wavefields generated using SRI with only partial boundaries: this also permits spurious or non-physical energy in the constructed Green's functions to be identified and either interpreted or ignored.

• 出版日期2014-6