Abstract: There are several kinds of filtering methods to diminish the noises.However,all of them are restricted by operating conditions,as a result,a satisfactory effect of filtering can not be obtained from actual data.Time variable filtering with S-transform overcomes the shortage that the filtering factors in traditional filtering and denoising approaches will not change with time and frequency variation.Seismic data are transformed to time-frequency domain by using the S-transformation methods,then,the noises at different time intervals and with different frequencies are zeroized partly.Finally,the seismic data after noise elimination are transformed into time domain again by using S-inverse transformation to achieve the effective signals needed.Based on theoretical and real seismic data calculation,it is believed that S-transform is really an effective method eliminating noises at different time intervals and with different frequencies.

Key words: S-transform, time-frequency analysis, time variable filtering, seismic data processing, denoising