Attenuation of Shear Noise in Seafloor Vertical Geophone Data Using Hybrid Radon Transform

초록

The seafloor seismic acquisition systems, such as ocean-bottom node (OBN) and cable ocean-bottom cable (OBC) arrays, provide multicomponent data essential for high-resolution imaging. Among them, vertical geophone recordings are often contaminated by shear-type noise (known as Vz noise), which arises from near-surface scattering and poor sensor coupling. This noise appears as incoherent energy in common shot gathers (CSGs) and as coherent hyperbolic events in common receiver gathers (CRGs), reducing data quality. We present a hybrid Radon transform-based method for attenuating shear noise in seafloor vertical geophone data. By combining linear and hyperbolic Radon transforms, the method enables effective separation of signal and noise. Two approaches are explored: 1) a geophone-only denoising in the CSG domain that reduces random noise and indirectly suppresses coherent noise in CRGs and 2) a joint sparsity recovery (JSR) method that incorporates hydrophone data as a reference to remove coherent noise in CRGs. Results on the Equinor Volve OBC dataset demonstrate effective noise attenuation and signal preservation, offering a practical solution for denoising multicomponent seafloor seismic data.

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