Constructive Reuse of Free-Surface Ghost Wavefields in Marine Seismic Data: A Propagation-Based Framework

Abstract

Recent advances in marine seismic acquisition and processing have substantially improved the separation of free-surface ghost wavefields. Building upon these developments, this study proposes a propagation-based framework in which separated ghost wavefields are treated as physically meaningful components that can be constructively utilised as additional observations. Starting from a finite inverse expansion of the ghost operator, a recursive formulation is derived and implemented through adaptive predictive decomposition. The formulation is subsequently extended to multidimensional wavefields through wavefield extrapolation, survey sinking, and reciprocity, allowing decomposition into components associated with real and mirrored sources and receivers. The separated wavefields are restored to a common acquisition geometry by survey sinking and combined through wavefield superposition, forming a preprocessing module that can be incorporated into conventional marine seismic processing workflows. Field-data examples acquired using a conventional shallow-towed airgun survey demonstrate improvements in reflector continuity, signal-to-noise ratio, and partial recovery of ghost-related spectral notches. The proposed framework therefore provides a processing-based complement to conventional ghost decomposition technologies and suggests a unified approach in which acquisition geometry and ghost processing are jointly optimised to maximise the information content of marine seismic observations.