scholarly journals Differential‐equation‐based seismic data filtering

Geophysics ◽  
1993 ◽  
Vol 58 (12) ◽  
pp. 1809-1819 ◽  
Author(s):  
Jianchao Li ◽  
Ken Larner

Suppressing noise and enhancing useful seismic signal by filtering is one of the important tasks of seismic data processing. Conventional filtering methods are implemented through either the convolution operation or various mathematical transforms. We describe a methodology for studying and implementing filters, which, unlike conventional filtering methods, is based on solving differential equations in the time and space domain. We call this differential‐equation‐based filtering (DEBF). DEBF does not require that seismic data be stationary, so filtering parameters can vary with every time and space point. Examples with two‐dimensional (2-D) synthetic and field seismic data demonstrate that the DEBF method accomplishes the desired time‐ and space‐varying temporal and move‐out filtering at lower cost than conventional frequency‐wavenumber‐domain filtering. The computational advantage in 3-D would be much greater.


1992 ◽  
Author(s):  
Jianchao Li ◽  
K. Larner


Geophysics ◽  
1973 ◽  
Vol 38 (6) ◽  
pp. 1042-1052 ◽  
Author(s):  
M. D. Cochran

By casting the problem of seismic signal detection as one of statistical detection theory, one can develop a myriad of detection statistics or detectors. Of these, one of the most promising appears to be sign‐bit semblance. This nonparametric detector makes use of only the sign bits of the seismic data and, hence, requires less storage and is faster to compute than other detection statistics. In addition, it is independent of the noise statistics, as are all nonparametric detectors. An automatic velocity analysis and interpretation program has been developed using sign‐bit semblance as the detection statistic. The statistical properties of sign‐bit semblance were such that this system could do a velocity analysis and an interpretation with no human intervention. In this mode of operation it yielded state‐of‐the‐art accuracy at greatly increased speed and with greatly reduced storage requirements. These results indicate that sign‐bit semblance can be used to advantage for certain other seismic‐data processing problems.



1992 ◽  
Author(s):  
Jianchao Li ◽  
K. Larner


Geophysics ◽  
2021 ◽  
pp. 1-35
Author(s):  
Hojjat Haghshenas Lari ◽  
Ali Gholami

Different versions of the Radon transform (RT) are widely used in seismic data processing tofocus the recorded seismic events. Multiple separation, data interpolation, and noise attenuationare some of RT applications in seismic processing work-flows. Unfortunately, the conventional RTmethods cannot focus the events perfectly in the RT domain. This problem arises due to theblurring effects of the source wavelet and the nonstationary nature of the seismic data. Sometimes,the distortion results in a big difference between the original data and its inverse transform. Wepropose a nonstationary deconvolutive RT to handle these two issues. Our proposed algorithm takesadvantage of a nonstationary convolution technique. that builds on the concept of block convolutionand the overlap method, where the convolution operation is defined separately for overlapping blocks.Therefore, it allows the Radon basis function to take arbitrary shapes in time and space directions. Inaddition, we introduce a nonstationary wavelet estimation method to determine time-space-varyingwavelets. The wavelets and the Radon panel are estimated simultaneously and in an alternative way.Numerical examples demonstrate that our nonstationary deconvolutive RT method can significantlyimprove the sparsity of Radon panels. Hence, the inverse RT does not suffer from the distortioncaused by the unfocused seismic events.











2001 ◽  
Author(s):  
P.P. Gupta ◽  
Kuldeep Prakash ◽  
Paramjeet Singh ◽  
M.N. Lakra


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