Using a Marchenko-redatumed Reflection Response as an Exact Boundary Condition

Marchenko Redatuming enables the creation of both virtual sources and receivers at an arbitrary depth level in the subsurface using only reflection data recorded at the surface and an estimate of the background velocity model. In this work, we perform full-waveform, target oriented modeling for a sub-domain of a 1D synthetic model using a combination of Marchenko-redatumed reflection responses and exact boundary conditions. We apply Marchenko redatuming to the two ends of the target region yielding Green’s functions for virtual sources and receivers at these positions, which illuminate the unknown embedding medium from below and above, respectively. Applying some simple processing steps to these Green’s functions enables us to use them as so-called exact boundary conditions for the target region. This procedure is aimed at establishing a link between the numerically modelled target region and the embedding background medium in order to include all interactions with the background medium. It appears that we can correctly account for the interactions without knowing the background medium in detail.