A unified inversion scheme for diffractions and passive events

We present a unified inversion scheme that can likewise be applied to passive events and different active-source diffraction data configurations. For the active case, we specifically target the weak but highly illuminating diffracted background through automated adaptive subtraction of the dominant reflected contributions, while only making use of the available near-offset channel. Based on local stacking and coherence evaluation, the recorded diffracted events are treated as passive source wavefields, which are characterized in terms of local properties of wavefronts emerging at the registration surface. In an industrial field data example offshore Israel, we show that the diffraction-based wavefront inversion of only the near-offset channel leads to results, which are in reasonable agreement with available geological interpretations. By application to an academic low-fold dataset recorded near Santorini, we demonstrate that the inversion scheme offers the opportunity to construct laterally resolved depth-velocity models even in the absence of large-offset recordings. In addition, we suggest a simple fully data-driven strategy to globally link the independently performed local coherence measurements that share the same origin in depth. Through this global characterization of events, we motivate to perform event-consistent statistics, which allow to estimate mean scattering or passive source locations and conveniently asses location uncertainties.