Another goal of deconvolution is to produce a wavelet with a simple phase character, ideally a zerophase wavelet, which is the same for every trace in the seismic dataset. Deconvolution of two discrete time signals in frequency. Convolution and filtering seismology and geophysics. Seismically, rock layers are defined by the densities and velocities with which seismic waves propagate through them. To understand deconvolution, first we need to examine the constituent elements of a recorded seismic trace the convolutional model. Deconvolution is a process universally applied to seismic data, but is one that is mysterious to many geoscientists. In conclusion, if the input wavelet is not minimum phase, then spiking deconvolution cannot convert it to a perfect zerolag spike as in frame k. Seismic unix has programs for performing many of the operations of. Early in our careers as geophysicists, most of us took at least one course on seismic signal analysis where we were taught that standard wiener deconvolution converts the minimumphase source wavelet in our seismic data to a wavelet with a phase spectrum that is zero and an amplitude spectrum that is broad and flat. Predictive deconvolution in seismic data processing in atala. When you do, the deconvblind function returns the output image j and the restored pointspread function, psfr, as cell arrays, which can then be passed as the input. Add pregressive nonblined deconvolution add blind kernel estimation implemented mehtod. Here is a page from one of my previous courses describing convolution. Jan 01, 2016 deconvolution is basically the opposite of convolution.
In 15 minutes, well take you from raw field data all. This is written in julia, a modern highlevel, highperformance dynamic programming language designed for technical computing installation. A seismic blind deconvolution algorithm based on bayesian. Using fourier mathematics, therefore, greatly decreases the computational cpu expense required to perform the filtering operation. Deconvolution attempts to compress the wavelet, thereby increasing the resolution of the seismic data. This page is intended to be a generic workflow for how to manually install seismic unix from source on a modern linux system. The commonest way to perform deconvolution is to design a wiener filter to transform one wavelet into another wavelet in a leastsquares sense.
Python modules and scripts for seismic data processing malcolmwseismic python. One way to extract the seismic wavelet, provided it is minimum phase, is to compute the spiking deconvolution operator and find its inverse. Deconvolution is a process that undoes the effects of convolution. Introduction a software developed by wolfgang stefan in cooperation with rosie renaut and ed garnero to deblur seismograms using total variation regularized deconvolution. Pdf processing seismic data with open source software. Deconvolution is process designed to enhance the vertical. They are computationally extensive requiring highend processors and huge memory capacities. Convolution gives the overlapp of one function with another function reversed in time. Deconvolution is basically the opposite of convolution.
It is possible to process gpr data wit su to use all the power of seismic processing tools to gpr data. Archlinux users may install seismic unix directly from aur. The deconvolution demo uses simple synthetic spike traces to illustrate both. It is usually used to restore a signal from a known convolution with a known response. A new iterative procedure for deconvolution of seismic ground. Predictive deconvolution remove shortperiod multiples most notably from relatively flat, shallow waterbottom the periodicity of the multiples is exploited to design a filter that removes the predictable part of the wavelet multiples, leaving only its nonpredictable part signal zerooffset gather after prediction decon. Robinson and sven treitel, covers the basic ideas and methods used in seismic processing, concentrating on the fundamentals of seismic imaging and deconvolution. The deconvolution is an imageprocessing technique that restores the effective specimen representation for a 3d microscopy images. Sunt is an adaptation for windows of seismic unix center for wave.
Because these techniques are in turn widely used in many scientific and engineering disciplines, deconvolution finds many applications. Specific instructions on installing seismic unix on ubuntu are also available. Note that if we need to multiply two polynomials, with coefficients uk and wk, we would use exactly the formula above. The image below is a single slice taken from a stack before and after deconvolution using these plugins. The iterative deconvolution 3d plugin uses a psf image zstack to correct the image contrast vs. Wsclean wsclean wstacking clean is a fast generic widefield imager. Seismic unix project is used not only in seismology but in other areas involving timedependent data, such as ground penetrating radar.
These two types of application of fourier deconvolution are shown in the two figures below. For example, a convolution can be used to model the filtering of seismic energy by the various rock layers in the earth. This video is a demo of start to finish processing using geomages gplatform software. Deconvolution by complex division in the frequency domain. Blind seismic deconvolution is the recovery of reflectivity sequence from the seismic records, when the seismic wavelet is unknown.
The concept of deconvolution is widely used in the techniques of signal processing and image processing. Predictive deconvolution in seismic data processing in atala prospect of rivers state, nigeria egbai, j. Where the recorded data can be modeled as a pure signal that is distorted by a filter a process known as convolution, deconvolution can be used to restore the original signal. On real data, gabor deconvolution is very competitive with the combination of wiener deconvolution and. Deconvolution is a filtering process which removes a wavelet from the recorded seismic trace by reversing the process of convolution. Deconvolution can also be performed on other types of data, such as gravity, magnetic or well log data. A step in seismic signal processing to recover high frequencies, attenuate multiples, equalize amplitudes, produce a zerophase wavelet or for other purposes that generally affect the waveshape. Center for wave phenomena colorado school of mines golden, co 80401, usa past support was received from. Matlab and octave have a builtin function for fourier deconvolution. The best known example of such kind is seismic unix, a free reflection.
The abcs of seismic exploration and processing, by enders a. Aug, 20 marine processing part 6 predictive deconvolution this sequence of blog posts will build up into a complete description of a 2d marine processing sequence and how it is derived. Center for wave phenomena colorado school of mines golden, co 80401, usa. In mathematics, deconvolution is an algorithmbased process used to reverse the effects of convolution on recorded data. Deconvolution, or inverse filtering, can improve seismic data that were adversely affected by filtering, or convolution that occurs naturally as seismic energy is filtered by the earth. If nothing happens, download the github extension for visual studio and try again. The concept of deconvolution is widely used in the techniques of signal processing and image. Early in our careers as geophysicists, most of us took at least one course on seismic signal analysis where we were taught that standard wiener deconvolution converts the minimumphase source wavelet in our seismic data to a wavelet with a phase spectrum that is zero and an amplitude spectrum that. It performs well in 1d or 2d, but its results are the most impressive for 3d volumetric data, especially when the psf is large axially.
The mathematical form of the convolution of two functions, a filter ft and a timeseries xt, is. Various software packages for deconvolution are available, both commercial ones and opensource ones. Marine processing part 6 predictive deconvolution this sequence of blog posts will build up into a complete description of a 2d marine processing sequence and how it is derived. Download deconvolution an intuitive image deconvolution and deblur application that can apply multiple different algorithms in order to improve the quality of your pictures. Laboratory manual for seismic data processing courses at. A step in seismic signal processing to recover high frequencies, attenuate multiples, equalize amplitudes, produce a zerophase wavelet or for other purposes that generally affect the wave shape. The seismic unix project is partially funded by the society of exploration. The complete software package is available electronically 6.
Compute deconvolution of two discrete time signals in frequency domain to study wave propagation. We have presented a nonstationary deconvolution algorithm based on the gabor transform that effectively corrects seismic data for source signature and attenuation. A seismic trace corresponding to an anelastic layered earth model can be sparsely represented by a structured dictionary of properly attenuated wavelets, through. The best known example of such kind is seismic unix, a. Simple example of wiener deconvolution in python github. Seismic unix is an open source seismic utilities package which was supported by the center. Seismic unx package a free open seismic processing, research, and educational software package. Convolution general formulae the resulting lake levels can be calculated by the following procedure, called convolution.
Renaut june 27, 2006 abstract this note provides complete details of the numerical algorithm implemented in the software package for signal resortoration of seismic signals 5. Laboratory manual for seismic data processing courses. Yes, doing some dimensional analysis trying to derive your formulae from wiener filter i found that might. Reflections on the deconvolution of land seismic data.
Seismic unix is an open source seismic utilities package which was supported by the center for wave phenomena cwp at the colorado school of mines csm. No processing sequence is definitive and techniques vary with time and software, however the idea is to provide a practical guide for applying seismic processing. Both courses have mandatory laboratory sessions that require the use of the seismic unix su processing software under the. Predictive deconvolution in seismic data processing in. The cwpsu seixmic unx su package is a software environment for seismic processing and seismic and wavepropagation related research. An interactive java application demonstrates the method and can be used to explore the impact of different parameter choices. You can use deconvblind to perform a deconvolution that starts where a previous deconvolution stopped. A seismic trace corresponding to an anelastic layered earth model can be sparsely represented by a structured dictionary of properly attenuated wavelets, through a nonstationary sparse deconvolution.
Geop320 seismic data processing and geop510 seismic data analysis. Hence, it increases resolution and yields a more interpretable seismic section. The package provides an instant seismic research and processing environment for users running on all unix and unix like operating systems, which include the operating systems whose names begin in u and end in x, mac os x, linux, free bsd unix, the windows bash shell, and the cygwin32 system for windows pcs. Deblur image using blind deconvolution matlab deconvblind. In line 7, c is deconvoluted from yc, in an attempt to recover the original y.
The best known example of such kind is seismic unix, a free reflection processing system. The parameters for deconvolution, velocity filter, mute. Gabor deconvolution easily beats wiener deconvolution on a nonstationary synthetic. Laboratory manual for seismic data processing courses at kfupm. Convolution of two series, ui, and wi, denoted uw, is. Convolution in coordinate space the image is equivalent to multiplication in frequency space.
Laboratory manual for seismic data processing courses using the seismic unix 1. Add pregressive nonblined deconvolution add blind kernel. Predictive deconvolution is the use of information from earlier part of a seismic trace to predict and deconvolve the. Deconvolution can also be used to determine the form of a convolution operation that has been previously applied to a signal, by deconvoluting the original and the convoluted signals. Seismic unix install on linux johnwstockwelljrseisunix. Compressive sensing in seismic signal processing is a construction of the unknown reflectivity sequence from the incoherent measurements of the seismic records. In this paper, a seismic blind deconvolution algorithm based on bayesian. We do this with seismic unx su, a free software package maintained and distributed by the center for wave phenomena cwp at the colorado school of mines csm.
Geop320 is a core course to geophysics undergraduate students while geop510 is an elective course to geophysics graduate students. Downloads are available as either unix gzipped tar files or windows zip files. The seismic unix project is partially funded by the society of exploration geophysicists seg, and by the center for wave phenomena cwp, department of geophysical engineering. Linux can download a live cd version called knoppix. The earth is composed of layers of rocks with different lithology and physical properties. In mathematics, deconvolution is an algorithmbased process used to enhance signals from recorded data. The basic trick is to fool su by using micro second as the time unit and centimeter instead of meter. Part 6 predictive deconvolution seismic reflections. Reflections on the deconvolution of land seismic data cseg. To use this feature, pass the input image i and the initial guess at the psf, psfi, as cell arrays. A new iterative procedure for deconvolution of seismic. Seismic data processing in 15 minutes geomage gplatform.
In seismology we create an impulse seismic energysource and this signal after interacting with the. A 2d seismic data processing primer, david forel, thomas benz, wayne d. Our objective is to introduce you to the fundamentals of seismic data processing with a learnbydoing approach. The richardsonlucy deconvolution is an iterative method based on bayesian inference for restoration of signal that is convolved with a point spread function the lucy function can be used to apply the richardsonlucy deconvolution method to a digital signal. Deconvolution compresses the basic wavelet in the recorded seismogram and attenuates reverberations and shortperiod multiples. Seismic unix su is a public domain seismic processing software package written and maintained by the center for wave phenomena at the colorado school.
This package provides a set of functions to deconvolve digital signals, like images or time series. In this paper, a seismic blind deconvolution algorithm based on bayesian compressive sensing is. The society of exploration geophysicists the gas research institute. Deconvolution is a mathematical process that allows the adjustment of the amplitude and frequency contents of a seismic ground motion applied at the base of the foundation in order to get the desired output at the damfoundation interface. You can download seismic unix, the field data, and the scripts, and recreate my.