seismic processing interface

GeBR: a free seismic processing interfaceRicardo Biloti, State University of Campinas & INCT-GP, Brazil

Copyright 2011, SBGf - Sociedade Brasileira de Geofsica.

This paper was prepared for presentation at the Twelfth International Congress of theBrazilian Geophysical Society, held in Rio de Janeiro, Brazil, August 15-18, 2011.

Contents of this paper were reviewed by the Technical Committee of the TwelfthInternational Congress of The Brazilian Geophysical Society and do not necessarilyrepresent any position of the SBGf, its officers or members. Electronic reproductionor storage of any part of this paper for commercial purposes without the written consentof The Brazilian Geophysical Society is prohibited.

Abstract

This article presents GeBR, a free graphical interfacecreated for the processing of seismic data, focused onteaching and research in this area. Besides allowingthe creation and management of processing streamsfrom predefined modules, GeBR allows adding newmodules, directly by the user. This feature turnsGeBR an interface to gather algorithms and programsproduced by innovative research.

The GeBR Project

In mid-1990, Eduardo Filpo, a geophysicist of the Brazilianoil company, Petrobras, was doctoral student in thegraduate program in Geophysics of Federal University ofBahia, Brazil. It was he who first realized the need for a freeinterface for seismic processing, able to integrate scientificoutput of that group in the area of Geophysics within aplatform in a way that makes it accessible beyond the limitsof the research group (Filpo, 2009 and Filpo, 2009b).

Over ten years later, in 2003, a first prototype interfacewas created by the Eduardo Filpo to assist in training newprofessionals who would work in seismic data processing.The prototype, named CIGEF, in allusion to the IntroductoryCourse in Geophysics (Curso Introdutorio em Geofisica,in Portuguese), taught to new geophysicists hired byPetrobras, was a proof of concept. It demonstratedhow beneficial for learning would be to have a graphicalinterface for processing, so that students could concentrateexclusively on the issue seismic processing itself, andno longer allocate time to the technicalities involved increating, editing, submission and control of shell scripts,as was usual until then.

In 2005, another prototype, now already called GeBR,was used in other training for employees of Petrobras,which took place in the Federal University of Parana,Brazil. With that interface was already possible to completethe processing of two lines of real data. In mid 2007,aiming to build a solid foundation for the development ofGeBR interface, a new version was written completely fromscratch, by Ricardo Biloti. Its over this version that is builtthe current interface GeBR and other related programs.

October 2007 marked the official launch of Project GeBR1to the community with its public presentation at the

1http://www.gebrproject.com

X International Congress of the Brazilian GeophysicalSociety, in Rio de Janeiro. Initially created to host thedevelopment of GeBR interface, the GeBR Project endedup gaining a larger dimension. Currently, the project aimsto encourage the integration of the Brazilian Geophysicalcommunity, providing a graphical interface for processingseismic data which, besides being useful for teachingstudents and professionals, could also be used as anaggregating point and vehicle for the dissemination ofresearch results, accelerating and enhancing their impactwithin the academic community and the society as a whole.

The GeBR interface

The main and most visible result of the GeBR Project is itsgraphical seismic processing interface. Unlike other freeinterfaces for creating seismic processing flows, such asTkSU2, GeBR is not only designed to the creation andsubmission of a processing flows, but also to the completemanagement of the processing of a 2D seismic data.

The GeBR is organized into four tabs (see Figure 1): (1)Projects and Lines, (2) Flows, (3) Flow Editor, and (4)Job Control. The first two tabs are designed to facilitatethe organization of the work, allowing the management ofseveral projects, each of which with their own lines andprocessing flows. The third tab is where the processingflows are assembled from processing modules alreadyavailable in the interface, the so called menus. Afterthis stage of assembly, each execution of a flow, a jobis created. The fourth tab is where the monitoring andmanagement of these jobs takes place.

Figure 1: GeBR interface. At left, it is shown the projectAGU 2010 with one line, Synthetic line. At right, it isshow some detailed information about that line, which isselected.

2http://www.henrythorson.com/interface.htm

Twelfth International Congress of The Brazilian Geophysical Society SBGf2011 169

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GEBR A FREE SEISMIC PROCESSING INTERFACE 2

Simplicity

The simplicity of the GeBR GUI is not a negative point,indicating lack of resources, but it is its greatest advantage,making it feasible for new users to take advantage ofthe interface almost immediately. In each tab there isalways a toolbar with buttons for implementing key actionsassociated with the context. Moreover, to avoid overloadingthe interface and also to make access to functionalitiesfaster, context menus (accessible through the right mousebutton) are available, presenting shortcuts for actionsrelating only the element (or group of elements) selected.

Extensibility

Another strength of the GeBR interface is that it is notstatic. New processing modules can be incorporated intothe interface. This feature allows that GeBR acts as adissemination vehicle for the new research products, in thesense that new programs can be immediately incorporatedinto the interface, being in this way readily available to use.

In principle, any program that can be executed throughthe command line of a shell can be integrated to GeBR.The more the program is controlled by options providedin the command line, the better the integration of it withGeBR. Currently, approximately 400 programs are alreadyintegrated into GeBR, mainly from Seismic Unix processingpackage (Stockwell, 1999).

The integration of a new program to GeBR isstraightforward. It is done through an auxiliary interface,also developed under the GeBR Project, known as DeBR.To complete this integration it is not necessary to haveaccess to the source code of the program, but only haveaccess to its usage documentation.

Organizational resources

To help users organize their work within the GeBR interfacethere is a hierarchy of information to be respected andexplored. The first level of this hierarchy is inhabitedby projects. Projects are responsible for hosting groupsof lines, an entity that occupies the second level of thehierarchy. Both for projects as well as for lines, it is possibleto define basic properties, like the owner or responsible forthe project, a title and a short description. For lines is stillpossible to define preferred paths. These paths are usedduring the construction of processing flows, to facilitate theorganization of the input and output files. The third level ofthe hierarchy is populated by processing flows. Just like forprojects and lines, it is also possible to set basic propertiesfor each flow.

Beside the lists of projects and lines or flows, there isalways a summary table displaying the main details aboutthe selected element. Besides the properties of theelement, for flows, for example, it is also shown when theflow was last ran, in which server, and which files areconfigured as input or output. GeBR also yields detailedreports for lines and flows containing the list of all the flowsof the line, tables summarizing the setup of each programof each flow, which are the input and output files for theflow, among other information. In addition, there is alsoplaceholder for users to add their own comments on theelement.

Each execution of a processing flow, a job is created

and displayed on the last tab GeBR interface. Whenselecting a specific job in that tab, the user has accessto all information generated by the processing flow, likethe current state of flow (submitted, waiting in a queue forexecution, running, completed, or stopped), the commandline that was actually used to run the job, error messages,run time, etc. Furthermore, users can stop a running flowor cancel the execution of a flow which is waiting in a queueto start its execution.

Resources to assembly and configuration of flows

To facilitate the construction of processing flows, the menusare sorted by categories (see Figure 2). The same menucan belong to more than one category, making it easy tofind. If the user still can not find the menu he or she wants,the user can do incremental search by the name of themenu. After finding the desired menu, by requesting theinclusion of it in the processing flow, all programs that makeup the menu will be included in the flow, independently,allowing the user to disable or even remove some of them.

Figure 2: Flow Editor tab. At left in the frame labeledFlow sequence it is shown the programs which compoundthe flow. In this case the second program (SU Simple XWiggle) is disabled. At right, it is shown the list of menuscategories, from which menus can be grabbed to assemblethe flow.

The configuration of each program of a processing flow ismade through a parameters dialog specific to the program.Figure 3 shows the parameters dialog for program S88Modeling. GeBR supports various types of parameters:numeric (integer, real, with or without limitation of range),text, multiple choice within a predefined list of options,Boolean values and files. This specificity allows that theinterface correctly validates the values filled out for eachparameter, turning the task of configuring programs lesserror prone.

Through this dialog of parameters, the user yet has accessto the documentation of the program in question (seeFigure 4), as well as to an external link that refers to a pagewith more details about the program. By means of a buttonat the bottom of the dialog, the setting of all parameters canbe returned to default values.

Besides being able to fill in directly the value of aparameter, it is possible to employ the dictionary ofparameters, where values can be labeled to be sharedamong programs of the same flow, or even between


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BILOTI 3

Figure 3: Parameters dialog for the program S88Modeling. Note that groups of parameters are defined toencompass parameters which are related to each other.These groups can be collapsed or expanded. Requiredparameters are displayed in boldface.

Figure 4: Detailed help for the S88 Modeling program.

programs of different flows (see Figure 5). For example, iftwo or more programs need to know a reference velocity,it would be better to fill this value in the dictionary andthen set the appropriate parameters of the those programsthrough the dictionary. Thus, if necessary, change thevalue of this property in the dictionary will have the effect ofthis change automatically propagate to all programs. Thedefinition of the parameters in the dictionary is done byscope. Parameters defined for the flow have priority overparameters set for the line, overlapping them if there arecollision of labels. Parameters can also be set througharithmetic expressions, employing values defined withinthe dictionary of parameters.

Figure 5: Dictionary of parameters.

Resources for flow execution

Through GeBR, it is possible to connect to multipleprocessing servers, allowing the user to submit flows forexecution on different machines and to control the progressof each job. Figure 6 shows the dialog where serversare registered. A flow may be subjected to immediateexecution or queued, being blocked from running until aspecific job has been completed. This feature, common inlarge machines, like clusters, is natively available on anymachine through GeBR.

Figure 6: Servers setup dialog. This dialog shows the listof registered servers. It is possible to see which server isactually connect, ask for connection or even stop a server.

Upon a job submission, GeBR itself makes severalvalidations in the generated job to minimize potentialproblems in the flow setup, alerting the user about themand blocking the submission until the problems have beingsolved.


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GEBR A FREE SEISMIC PROCESSING INTERFACE 4

Technical aspects

The GeBR interface, as well as other softwares developedby the GeBR Project, is developed mainly in C, employingthe graphical toolkit GTK+, among many other commonlibraries, all of them being highly portable. In fact, to beable to provide an interface to a wide range of systems, it isalways a concern of the project choose portable libraries.Yet in this regard, all information filled in the interfaceis stored as XML, which is a standard format wheneverportability is an issue to be considered.

All code produced by the GeBR Project is released asfree software, under the terms of the GNU General PublicLicense. This guarantees unrestricted access to the codeto everyone, who might be interested.

References

Filpo, E., 2009, GeBR The geophysical interface of Brazil(GeBR A interface geofsical do Brasil, in Portuguese).Boletim SBGf, No. 1., pp. 10.

Filpo, E., 2009b, A rescue of the history of GeBR (Umresgate da historia da GeBR, in Portuguese). URL:http://www.gebrproject.com/documentation/

historia-da-gebr.

Stockwell, J.W., 1999, The CWP/SU: Seismic Unixpackage, Computers & Geosciences, Vol. 25, No. 4., pp.415419.

Acknowledgments

I would like to thank PETROBRAS for financially supportthis work, through its Research Net in Applied Geophysicsand the sponsors of the WIT Consortium.


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seismic processing interface

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