The time frequency property of S transform and its generalization

Seismic signals have nonlinear,non-stationary properties.Using time frequency method to process seismic signals could reserve the primary information of the data in maximal extend,and accurately analyze the properties of the data in the time frequency domain.Until now,there are many time frequency methods,such as the short time Fourier transform(STFT),the wavelet transform(WT) and the matching pursuit method(MP),and so on.The S transform is a new time-frequency method developed in recent years.The transform takes both the advantages of short time Fourier transform and the wavelet transform,that is to say the transform has phase information just as the STFT and its time frequency windows adjust adaptively according to the non-stationary signal just as the WT.These advantages make it is used widely in geophysics area.However,there are few papers quantitatively discussing the lime frequency properties of the S transform.This paper points out the shortages of the S transform through experiments,finds the root of the shortages by theories analysis and points out the ways to improve the S transform. Furthermore,experiments conducted validate that the remedy ways are indeed effective.