Rough Sea Surface Reflection Coefficient Estimation and Its Implication On Hydrophone-Only Pre-Stack Deghosting

Deghosting a hydrophone-only measurement requires accurate description of seismic wavefield scattering at the sea surface. In recent years, attempts have been made to deghost hydrophone-only data using a frequency and angle dependent sea surface reflection coefficient. Nevertheless, rough sea surface reflection coefficients have both specular and non-specular contributions. In pre-stack hydrophone-only deghosting, the non-specular contributions are often assumed to be negligible. In this paper, we characterize the sea surface scattering using numerical modelling and quantify the contributions of both specular and non-specular reflections from two different realistic sea states. The results show that the magnitude of the specular reflection coefficient decreases with frequency and increases with angle. Moreover, the rougher the sea surface, the higher the magnitude of the non-specular contributions.