Abstract
Conventional Marchenko redatuming can retrieve the Green’s function at a virtual receiver inside a heterogeneous medium from single-sided reflection data. It requires minimal a priori knowledge of medium properties but assumes the medium to be lossless. The dissipative Marchenko scheme, on the other hand, can retrieve the Green’s function inside a lossy medium but requires double-sided access to the lossy medium in order to obtain the reflection response of its corresponding effectual medium with negative dissipation. Here, we implement the dissipative Marchenko scheme both numerically and experimentally, and successfully redatum full sound wavefields in a one-dimensional (1D) waveguide. To achieve this, we first quantify the medium attenuation using the nearly constant model to facilitate numerical modeling. Then, we numerically retrieve two sets of focusing functions that are required by the scheme, by iteratively reemitting the time-windowed and time-reversed signal from a single side of the dissipative and effectual media. Without any knowledge of the medium properties, we experimentally retrieve the desired focusing and Green’s functions inside the physical wave tube from double-sided scattering data measurements. We show that both offline processing and real-time focusing can achieve similar accuracy. True-amplitude Green’s functions can also be obtained but require a scaling correction. The reconciliation of numerical modeling and physical experiments is an important step in establishing the applicability of the Marchenko methods for attenuative media.
10 More- Received 13 March 2018
- Revised 8 June 2018
DOI:https://doi.org/10.1103/PhysRevApplied.10.044022
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