Time-Reassigning Transform for the Time-Frequency Analysis of Seismic Data

A time-frequency (TF) analysis (TFA) method plays a significant role in seismic signal processing. However, traditional seismic TFA techniques always provide blurred TF representations (TFRs) with low temporal resolution. The transient-extracting transform (TET) is an effective TFA tool that improves the temporal resolution of TFR of nonstationary signals. However, the TET suffers from nonreassigned point (NRP) problem, which can result in unreliable seismic interpretations. In this article, a novel TF transform is proposed to address this problem, named the time-reassigning transform (TRT). In the short-time Fourier transform (STFT) domain, this TRT searches for local maximum points of the spectral energy along the time direction instead of searching for group delay (GD) fixed points such as the TET. At these points, the STFT coefficients are reassigned into a sparser TFR while eliminating the NRP problem, as verified by two synthetic signals and a simulated seismic trace. Finally, application analysis on a geological model and field seismic data shows that the proposed TRT is a potential seismic data analysis tool.