Adaptive Ground‐Roll Suppression Based on Adaptive Chirp Mode Decomposition in the <i>Fx</i> Domain

ABSTRACT Ground roll severely affects the signal‐to‐noise ratio of seismic data. Characterized by low frequency, strong energy and low‐velocity, it significantly masks the primary reflections. Ground roll manifests as a non‐stationary, frequency‐modulated signal in the fx domain. To separate the intrinsic mode functions (IMFs) containing ground roll, we propose a pre‐stack ground‐roll suppression method based on adaptive chirp mode decomposition in the fx domain ( fx ‐ACMD). The fx ‐ACMD algorithm iteratively optimizes through three steps: demodulation, adaptive filtering and reconstruction. This framework incorporates greedy recursive decomposition and adaptive bandwidth updating. The application of time‐varying demodulation operators makes it particularly suitable for adaptive mode decomposition of non‐stationary signals. By further exploiting the localized high‐wavenumber characteristic of ground roll in the fx domain, we propose fx ‐adaptive ACMD ( fx ‐AACMD). The fx ‐AACMD operates without manual intervention and applies the data‐driven IMFs selection strategy to automatically identify ground‐roll‐containing IMFs. Through localized filtering, it effectively suppresses ground roll while maintaining stability and preserving amplitudes. Tests on synthetic and field data confirm that the proposed methods achieve effective suppression of ground roll.