Imaging with surface-related multiples using linear and non-linear modelling

Seismic reflection imaging aims to generate a representation of the subsurface of the earth using acoustic or elastic waves recorded in the form of seismic data. During the processing of the data for imaging, we pick a part of the data as signal and discard the rest as noise. Since so-called primary wavefields carry the single-scattering reflection response of the subsurface, they are assumed to be sufficient to carry out reflection imaging. This also means that significant effort is devoted towards removing not only the noise but also the multiple reflection events to avoid imaging artefacts, also known as cross-talk. Surface-related multiples are the multiples generated during the marine acquisition by at least one downward reflection at the water-air boundary, and tend to be the strongest in amplitude compared to the other multiples. Over the past several decades, many novel techniques have been developed to remove the surface-related multiples effectively. While we are getting better at primary-multiple separation, it is still a very challenging and expensive problem. In recent years, multiples have gained recognition as valuable signals, not just noise. Multiples also contain the reflection responses of the subsurface and since they travel different paths they often contain additional information about the subsurface compared to the primaries-only wavefields. Imaging with primaries and multiples without separation is the way forward as it avoids the expensive multiple removal steps along with providing (potentially) additional illumination from the multiples...