Seismic Linear Noise Attenuation Based on the Rotate-Time-Shift FK Transform

Linear noise attenuation is a troublesome problem in a variety of seismic exploration areas. Traditional methods often use differences in frequency or apparent velocity to separate the signals and linear noise. However, these applications are limited when the characteristics of the aforementioned differences between signals and linear noise are too small to be distinguished. For this reason, we proposed a rotate-time-shift FK (RTS-FK-CS) method based on compressed sensing (CS). Based on the deblending concept, the proposed method flattens the linear events using the rotating coordinate system and performs a lateral time shift for each time point. Because of the random time shift, events with different apparent velocities from the linear noise are disrupted as “a deblended data in common receiver domain,” and events with similar apparent velocities have a difference in frequency. To suppress linear noise, we apply the CS reconstruction algorithm in the frequency-wavenumber (FK) domain. The random time shift uniformly distributes the energy near the dominant frequency to each frequency in the FK domain, enhancing the sparsity in the transform domain. The proposed method can effectively suppress linear noise and reduce the loss of events whose apparent velocities and frequency are similar to linear noise. Synthetic and field data tests visually and quantitatively confirmed the superiority and robustness of the proposed method.