Seismic time-frequency analysis using the vertical second-order synchrosqueezing transform

Time-frequency representation (TFR) of seismic signals provides a source of information that is usually hidden in the Fourier spectrum. The short-time Fourier transform (STFT) and the wavelet transform are the traditional approaches to obtain the TFR of the signals. However, they have a trade-off between time and frequency resolution. As a solution, the STFT-based synchrosqueezing transform (FSST) was proposed recently. It is an extension of the short-time Fourier transform, and can achieve a more energy-concentrated TFR. Unfortunately, the FSST has limitations in dealing with fast varying instantaneous frequencies, which is often the characteristic of seismic data. On this occasion, the vertical second-order synchrosqueezing transform (VSST) was recently proposed. This new tool produces a more sharpened TFR allowing the identification of instantaneous frequencies in seismic signals to highlight individual components. We introduce the VSST method, and show its validity and effectiveness for seismic signal processing applications.