Angle domain method to remove NMO stretch

摘要

NMO stretch is a phenomenon of signal distortion caused by wavelet stretch in applying NMO correction. The common method to remove the effects of NMO stretch in conventional seismic data processing is hash muting the traces distorted severely, most at farther offsets, which apparently reduces the fold of stack and thereby reduces resolution of seismic data. In the near-surface seismic data processing, it is of great importance to increase the fold of stack by removing NMO stretch because the stretch effect on shallow reflectors is bigger than that on deep reflections in same offsets. It is indicated by our study that the NMO stretch is not stationary in offset domain and the methods developed currently for correction of the stretch are not very effective or cumbersome. Following the previous work on this subject, we develop a method to remove the NMO stretch in reflection angle domain by applying a stationary spectral shaping operator because it is found that the mount of stretch is same for all samples in angle domain. The results from synthetic data and field data show that implementation of the method is correct and the method has great prospective application to improve the stack resolution, AVA analysis and migration.