HORIZONTAL REASSIGNMENT SYNCHROSQUEEZING TRANSFORM FOR TIME-FREQUENCY ANALYSIS OF SEISMIC DATA

摘要

The short-time Fourier transform (STFT)-based synchrosqueezing transform (FSST)is a special type of reassignment method that achieves a compact time-frequencyrepresentation (TFR) for a class of nonstationary signal. However, for the signals with astrongly varying instantaneous frequency, the FSST method is always not desirable. Toaddress the problem, a new method, termed as horizontal reassignment synchrosqueezingtransform (HRSST), is proposed in the paper. By means of an unbiased group delay (GD)estimation, the HRSST provides a sharped TFR for transient signals in which thetime-frequency ridge is nearly parallel with frequency axis. Through synthetic data, theproposed HRSST method is determined to be an effective and robust tool which providessuperior results over some classical TFA techniques such as STFT and FSST. Finally,two field examples are employed to further demonstrate its potential in time localizationcharacterization and subsurface geological structures delineation with high precision.