T. KLIMENT

MetainforMation infrastructure for Geospatial inforMation

KeY WorDs

• Metadata,• Metainformation, • Metadata Catalogue,• Metainformation System,• Metainformation Portal, • Catalogue Service

aBstract

The Infrastructure for Geospatial Information consists of an information component, where the bearers of geoinformation are geospatial data, and a metainformation component. The bearers of metainformation are metadata, which describe these geospatial data. Metadata serve as a tool for discovery, retrieve and evaluation of geospatial data within the Infrastructure of Geospatial Information. In order to acquire metadata from a metadata producer to a metadata consumer, the implementation of various tools – components of Metainformation Infrastructure for Geospatial Information is required. This paper describes the main principles and components of Metainformation infrastructure and the possibility of using open source tools for their implementation in practice.

Tomáš KLIMENT email:tomas.kliment@stuba.skResearch field: Spatial Data Infrastructures (SDI) -Metadata,DiscoveryService,InfrastructureforSpatialInformationinEurope(INSPIRE)

Address:DepartmentofTheoreticalGeodesy,FacultyofCivilEngineering,SlovakUniversityofTechnologyinBratislava,Radlinského11,81368,Bratislava,Slovakia.

Vol. XVIII, 2010, No. 2, 19 – 25, DOI: 10.2478/v10189-010-0007-3

1 introDuction

Geospatial data (GD) represent agreat treasure through theirform of inputs to various projects in our society. The results ofthese projects bring new information and knowledge, whichcan be subsequently used as inputs to other projects. Since thebasis of this process is high quality easily accessible GD, it isnecessary to provide opportunities for easy discovery, evaluationandretrieval.ThesearethekeywordsofonepartofInfrastructureofGeospatial Information(IGI),whichwecandenominateas theMetainformationInfrastructureforGeospatialInformation(MIGI).Thesecomponentsareusedinthediscoveryofmetadatamanagedwithin geocatalogues and thereafter the evaluation of GD andretrieval for the end user of IGI. Therefore, metadata (MD) andGeocataloguearethebasiccomponentsthatfacilitateaccessibilityand interoperability of the geospatial resources provided by IGI(Nogueras-Isoetal,2005).

The paper describes the theoretical aspects ofMIGI componentsandthepractical testingandmodificationsofchosenopensourcetools from the fieldofMDeditors, theMetainformationSystems(MetaiS), the implementation of Catalogue Service and desktopGIS (Geographic Information System) tools, which the authorcarried out in the written part of his dissertation examination(Kliment, 2009). Main objective is an assessment of the actualstatusoftheimplementationoftheInternationalstandardsfordigitalgeographic information (ISO/TC 211 Geografic information),technical specifications (OGC - Open Geospatial Consorcium)and adescription of the functionality and technology used in thecreationofthesetools.Opensourcetoolsareanexcellentsolutionfor the implementation of components of MIGI in practice,particularlyinthenon-commercialfield,becausetheyareusuallyfree andoffer open source code for additional development. It ispossible to install, test andmodify these tools according toone’sspecificneeds.

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2 Main coMponents of MetainforMation infrastructure for Geospatial inforMation

ThemaincomponentsofMIGIareMetadataCatalogue(MetadC),MetaiS,MetainformationPortal(MetaiP),theimplementationoftheCatalogueService–thesecomponentsarecommonlyimplementedascomplexsolutionnamedasGeocatalogue.Additionalcomponentsas Geoportals and desktop GIS tools, which have nowadaysfrequently implemented management and distribution of MDmay also be classified as components of MIGI. Aconceptualmodel of IGI with main focus on MIGI components and theirrelationsisshowninFigure1.Thebasic“metainformationstores”are MD warehouses, which we called the Metadata Catalogues.Each MetadC may comprise of one or more MD databases.For centralized MD management of particular MetadC withinorganization is implemented MetaiS. The particular MetaiS forgroupoforganizationarecentralizedtoMetaiPwithinregion,stateor union.MetaiP provides cross connection ofMIGI componentstoentireIGIandmaybeeither independentcomponentorpartofGeoportal–mainwebaccesspointtoIGIeithernational(NIGI)ormulti-national level.Themain “engine” to servemetadata amongalreadymentionedelementsiscatalogueservice.

2.1 MetaData anD MetaData-cataloGueTheterm“metadata”canbemosteasilydefinedasdataaboutdata,respectively information about data (metainformation). MD canbe regarded as summary information that can be attributed to anabstractorrealobject,processorphenomenon.ThismeansthattheMDmusthavemeaningandapplicationinvariousfieldsofhuman

society.EveninthedomainofIGItheuseofMDismostimportant,because it improves thequalityandquantityofGDgainedwithintheinfrastructure.DetailedaspectsoftheMDdomainaredescribedwithin authors written part of dissertation examination (Kliment,2009),whichamongothersdefinesthebasiccharacteristicsofMD,namely,thatmetadatashould:• reflectthemostactualstateofadescribedsource,• constituteanauxiliaryelementforunderstandingthefunctionalityandcontentofthesource,

• beportableandconsistent,• facilitatediscovery,comparisonandassessmentofthesourcesofavarietyofpointsofview,

• beenteredinanappropriatewayforcommunication,distribution,interpretationandprocessing,

• facilitate the sharing and exchange of information about thesource,

• provideinformationaboutthepointofaccesstothesource(URL,etc.).

The result of this approach is aset of the MD records, whichdescribes the GD. These MD records are commonly centralizedwithinastoragearea.ThestorageareacanbedefinedasaMetadataCatalogue, inwhichwecan imaginealargesetofMDrecords inadatabase.ThebasisforMetadCisthattheystorealargenumberof heterogeneous MD (descriptive information about differentresources).MDmanagement inMetadC can be performed usingatoolfortheadministration,whichcanbeapartoftheinstallationof database management system (DBMS), or by using aMeta-InformationSystem.SecondapproachisstandardwithinIGI.

2.2 MetainforMation sYsteM anD MetainforMation portal

AMetaiS isageneralname forany informationsystem,ofwhichthe database is aMetadC (Ožana, 2007). The key features andfunctionalities of any MetaiS are shown in Figure 2. AMetaiSshouldprovideanattractive,user-friendlyinterfacefortheeffectivediscovery ofMD and the display of their content. In addition tothese basic functions, MetaiS should provide the functions forMDmanagement (creating, editing and deleting ofMD records).Forthedistributionofexistingrecordsitshouldprovidefunctionsto import records from other systems or export existing recordsfor further use in other systems. From the point of view of thesystem and the MD administrator, aMetaiS should provide thefunctionsforitsadministrationandalsotheend-userfunctionsforuser support in the formof documentation and tutorials.The keyfunctionfromthepointofviewofthecommonuser(MDconsumer)ofMetaiSis thediscoveryandviewofMDrecordscontent.With

Fig. 1 A conceptual model of IGI – metainformation part – MIGI

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21MetainforMation infrastructure for Geospatial inforMation

regard to aquery forGD, it is necessary to ensure that aMetaiSshould provide classical full-text discovery and also so-calledextendeddiscovery,whereonecandefinetheadditionaldiscoveryparameters,forexample,spatial,temporalandthematicparametersin order to enhance the relevancy of the results of the discoveryprocess.AMetaiSmaybedivided intopublic andprivateMetaiSandcorporateanddepartmentMetaiS(Ožana,2007).TheseMetaiSmaybeconnectedtoMetaiPwithinMIGI.AMetaiPisatoolwhichmakesMDrecordsfromvariousMetaiSavailable(forexample,thegovernment departmentMetaiS inSlovakia) in auniformmethodwithin acentral interface (See Figure 3). AMetadC of aMetaiPmaintainsonlyaminimumsetofMDaboutgeospatialsourcesandMDaboutfederatedMetaiS.TheaimistosimplifythediscoveryofMDrecordsfromavarietyofMetaiSfromacountryoraregion(forexample,theEuropeanUnion)fortheend-usersofIGI.ItunifiesthedisplaymethodofMDcontentandmanagementoftheMDrecordsofvarioustypesandnatures(heterogeneousMDrecords).AMetaiPis the central point of access toMD, e.g., on anational ormulti-nationallevelofanIGI.

2.3 cataloGue serViceACatalogue Service implementation on the web is at the top ofMIGI,particularlyanexampleofaCScalledtheCatalogueServicefortheWeb(CSW)(OGC,2007a).WithCSWaMetaiSorMetaiPsends user query against MD records content, which are storedinMetadC.Theuserquerycanbealsosend to federatedCSWtoperformdistributeddiscovery.Theserviceresponds to therequestofaclientbydisplayingrelevantMDrecordsbasedonthequery’sparameters.Areference model of the catalogue services adoptedby the OGC (OGC, 2007a) for the development of interfacesof these services is shown in Figure 4. The model defines boththe possibilities of the discovery of geospatial resources fromthree possible ways (alocal service MetadC, services (mapping,downloading, etc.)within geospatial sources and other CS in thedistributednetwork)andtwointerfaces(OGCande.g.proprietarysolution).

2.4 GeoportalGeoportalrepresentsagatewaytotheIGIontheweb.Itisinfactaportal, that may provide the possibility for users to discover,view, download, transform and process geospatial sources. TheMetaiPcanbeapartoftheGeoportal.Geoportal’sarchitectureisbasedonwebservicesthatareinvokedbyuserswithinitsinterface.Hence, it concerns the Service-OrientedArchitecture (SOA), theprinciplesofwhicharedescribedwithinwrittenpartofdissertationexamination (Kliment, 2009). The general implementation oftheGeoportal complex is defined by the 4main services (PortalServices, View Service, Data Services, and Catalogue Services)(Ožana, 2007). The architecture of the Geoportal divides thewhole system into smaller logical elements that are autonomous

Fig. 2 Metainformation System

Fig. 3 Metainformation Portal

Fig. 4 A reference model of the Catalogue Service defined by OGC (OGC, 2007a)

MetadataCatalogue

CSW

Client Visualization

Resources

Resources

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and provide for the partial functionality of the system. Theseelementsareeasiertomodifyandadjust.Thearchitectureensuresthe openness and accessibility of the system, particularly on thebasis that these services are built on ISO standards and OGCspecifications, which have gradually been introduced into mostsystemswithinthegeospatialdomain.

2.5 DesKtop GisNowadays many desktop GIS tools have implemented functionsfor the creation,management, distribution and publishing ofMDaboutgeospatialsources,withwhichwemaybeworkingintheseenvironments.Itispossibletoactuallyworkwithgeospatialsourcesand their descriptions and then publish MD for instance in theMetaiS.ThesetoolsrepresentadesktopclientofIGI.

3 Main Description anD functionalitY of cHosen open source tools for tHe iMpleMentation of tHe MiGi coMponents

FollowingpartofpaperdescribesopensourcetoolsthatwerechosenaccordingtotheirwideusagewithinIGIdomain(http://geonetwork-opensource.org/geonetwork-nodes)andauthorpracticalexperiencesachievedwithinbachelor,masterandparalleldoctoralstudy.The first tool is themetadata editorCatMDEdit (www.catmdedit.sourceforge.net),whichwasdevelopedinSpainattheUniversityofZaragoza.Thetoolcanbeusedforthecreationofmetadatarecordsonalocalbasis,withaspecialfocusonthedescriptionofGD.Thistoolprovidesbroadfunctionalityforthecreation,managementanddistribution(export/import)ofmetadatawithregardtothestandardsISO,namelyISO19115:2003Geographicinformation–Metadata(ISO,2003) forMDcontent and ISO/TS19139:2007Geographicinformation – Metadata – XML schema implementation (ISO,2007a) forMDcontentcoding.Tool supportscurrentactivities inEurope in IGI domain as well in metadata creation possibilitiesaccording to INSPIRE (Infrastructure for Spatial Information inEurope) (Directive, 2007)CatMDEditwas developed in the Javaprogramming language and distributed as open source softwarethrough the web. It is multiplatformed, and can be installed inMicrosoftWindowsandUNIXoperationsystems.Itisamultilingualtool and currently supports six European languages and can betransferred into the Slovak national environment. It providesaveryuser-friendlygraphicuserinterface(GUI)(SeeFigure5).Itsadditionalfunctionalityisdescribedin(Kliment,2009).Another tool is the MetaiS GeoNetwork opensource (www.geonetwork-opensource.org), which began as acatalogue system

for geospatial sources - Geocatalogue. Currently, this softwareis widely used as an IGI base worldwide. The GeoNetworkopensource is an application, which allows users to implementthe comprehensivemanagementofmetadata in adistributed formvia the Internet. It is based on standards and provides geospatialdata through MD, which can be freely shared among differentcommunities.Thesystemoffersinterfacesforeasyandquickaccesstogeoresources.GeoNetworkwasdevelopedasawebapplicationand among all technologies that are usedwithin its developmentJavaplatformistheirconnectionlink.ThesystemhasaJettywebserverwithintheinstallationpackageandalsosupportstheApacheTomcatserver.GeoNetworkstoresalldataintherelationalDBMS.It supports MySQL, PostgreSQL and Oracle DBMS. To accessthe DBMS system uses the Java Database Connectivity (JDBC)application programming interface (API), which defines how theclientmayaccessthedatabase.ThetestedversionofGeoNetworkis v. 2.0.2 fromApril of 2008. It provides anumber of upgradesfromtheprevious2.0.1versionfromSeptember2007.Thecurrentversionoffersamoreintuitiveanduser-friendlyinterfaceandtoolsfor user interaction with the system. The discovery interface hasbeen completely redesigned for easy and interactive discovery.The systemhas implementedGeoServeras themapserver.Usersno longerneedthedataonlyoverlapwith theavailableWebMapService(WMS)(ISO,2005andOGC,2006),butcandirectlycreatetheir ownWMS for other users of the system without installingadditionalplug-ins.TheGeoNetworkisinaccordancewithstandardISO 19115 (ISO, 2003) and MD are encoded regarding to ISO19139 (ISO, 2007a).The system has abuilt-inMD editor,whichcontainsMD schemas such as the Dublin Core (ISO, 2009), the

Fig. 5 GUI of the MD editor CatMDEdit

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FederalGeographicDataCommittee(FGDC,1998)andISO(ISO,2003) for the creation ofMD records.MD can be created in thedefault, advanced or XML views. The current version providesanumberofdifferentinterfacesforharvesting,whichallowuserstoconnect theirserver tovariouscataloguesaroundtheworld in thedistributednetwork.Thisistheresultofopen-sourcereferencesoftheOGCconsortiumforCSW.Harvestingisfullycompatiblewithversion2.0ofGeoNetworknodesCSW.Another tool is the implementationofCSWdeegreeWebCatalogService v. 2.2 (www.deegree.org), which is being developedin Germany at the Department of Geography at the Universityof Bonn. In the deegree project Java solutions are developed,which provide themain building blocks for the IGI.All the Javamodules are controlled by one central servlet. Most web serverssupport this technology, so this fact makes the deegree solutionsauniversal product. The actual version of the deegree CSW 2.2serviceimplementatinworksinaJavaRuntimeEnvironment(JRE)in versions 1.5.x and is controlled byApache Tomcat servlet inversions 5.5.x and higher. DBMS is PostgreSQL with aPostGISextension,whichenablesthesavingofspatialobjectstoadatabase.The entire architecture is developed according to the OGC andISO standards mentioned above. The implementation of deegreeCSWisable toprovidemetadata indifferentstandards inparallelwiththesamedatabase.ThisispossiblebecausetheCSWusestheExtensible Stylesheet Language Transformations (XSLT) processtotransformtherequestsandresponsestotherequiredformat.Theservicedoesnothave itsownmodule toaccess theMD,butusestheOGCWebFeatureServiceoperations(OGC,2005)(SeeFigure6).CSWdeegreeprovidesuserswithahighdegreeofflexibilityinviewof its configuration options andoutput formats.The serviceworkswithawiderangeofdatasourcesandserverenvironments.The configuration of CSW deegree requires editing XML files,whichmanageandcontrolthefunctionalityoftheserver.

The installation of theCSW contains asimpleWeb client.UsingXMLmessages the user can discover, insert, delete and editMDfromaMetadC.TheresponsesarealsoanswersintheformofXMLviewsThelatesttoolisgvSIGadesktopGIS(www.gvsig.gva.es),whichisapartoftheprojectsundertheOpenSourceGeospatialFoundation(www.osgeo.org). It allows the user to work in the user-friendlyGUI, in which it is possible to create interaction with the OGCWeb services (WMS, CSW). The architecture is based on theJava technologies. In the version gvSIG 1.1.1 ametainformationcomponentisalsoimplemented(SeeFigure7).Theprogramallowsthe user to discover and viewMD in the basic installation fromremoteMetadCbydefiningtheURL(UniformResourceLocator)address of CSW. It is possible to install the prototype of aMDextension,whichallowscreating, importig,editingandpublishingtheMDintheISOCoreschema(ISO,2003).

4 testinG – oVerall Description anD test oBJectiVes

Amainobjective for abovedescribed tools isusability testing forworkflowsthatcouldbeperformedeitherbyMDproducerorMDconsumer or establisher of IGI.To achieve thismain objective 4testingscenarioswereproposedandperformed:1.MDproducercreatesaMDrecordfromthescratchbyCatMDEditfollowing ISO (ISO, 2003) and INSPIRE (Directive, 2007)specific constraints and.then distributes (export/import) createdrecordinXMLformattotheMetaiSGeoNetworkopensource.

2.MD producer extracts MD from geospatial data (provided bySlovakEnvironmentalAgency)inGeographyMarkupLanguageFig. 6 Architecture of deegree CSW

Fig. 7 GUI of metainformation component of GIS tool gvSIG

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– GML (OGC, 2007b and ISO, 2007b) and distributes to theMetaiSGeoNetwork.

3.MDconsumersearches,discoversandviewsMDrecordscreatedandimportedinprevious2sectionsviaboththewebclientoftheMetaiSGeoNetworkandthedesktopclienttoolgvSIG.

4. IGIestablisherinspectsandverificatesofthefunctionalityoftheimplementationofdeegreeCSWandmodificatesGUIofMetaiSGeoNetworkopensource.

In the following part, paper provides the main assessmentcharacteristicsoftestedtoolsregardingtoproposedtestingscenariosand description of modification of GUI performed on MetaiSGeoNetworkopensource.All testscenariosaredescribed indetailin(Kliment,2009)

4.1 MoDifications of tHe GeonetWorK opensource

It is possible to modify many things in open source software,because we can freely adjust all the configuration files (mostlyinXML form) and source code aswell.We can change theGUI(logos,colors,fonts,“GEOlook”)orwecanlocalizethesetoolsinthenationalenvironmentand,at lastbutnot least,wecanextendthefunctionalityofthistoolbysourcecodemodifications.TheGUIwere changed and localized to national environment of Slovakiabyauthor.ThevisualpresentationofGeoNetworkcanbeadjustedthroughtheediting:• Documents for visualization – eXtensible Stylesheet Language(XSL),

• CascadingStyleSheets(CSS).ByeditingXSLdocumentswhicharestoredinthelocaldirectoriesof asoftware installation, it is possible to change the generatedHyperText Markup Language (HTML) code and thus changethe arrangement of the web pages generated. By editing CSScan be accomplished modifications of the visual presentation ofthe generatedHTMLweb page. The CSS are stored in the localdirectoriesofthesoftwareinstallationfolderaswell.TheactualinstallationoftheGeoNetworkiscompletelytranslatedinto four languages (English, French, Spain and Chinese). TheauthorlocalizedGUItoSlovaknationalenvironment.Theprocessoflocalizationconsistsofthreebasicsteps.InthefirststepitwasnecessarytomodifyantheexistingmenuofGeoNetwork,usedtochange the application language.Thismenu is defined in the filebanner.xsl.The author added the required code to the appropriatesiteinthisfile.Inthesecondsteptheauthormodifiedthecontentsof the string.xml files in each language folder and added code:<sk>Slovenčina</sk>tothesefiles.Inthethird“main”stepafolderwascreatedfortheSlovaklanguage,andallthefilesfromEnglishlanguage folderwere copied. In the final localization process thestringsintheelementsofallXMLfilesweretranslated.Thefinal

GUI, which was localized to the Slovak national environment isshowninFigure8.

4.2 eValuation of tHe testeD toolsCatMDEditisaveryuser-friendlyandsimpletool,whichprovidesbroad functionality for the creation and management of MD forgeospatial resources. It has asimple installationprocess anddoesnotneed touseany Internetconnectionduring itsuse,whichcanbe on alocal basiswhen creating alarge number ofMD records,respectively their generation, complementation and, validation.TheirexporttoXMLfiles,whichisinaccordancewithISO(ISO,2003 and ISO, 2007a) standards, is an advantage in phase ofdistributionof generatedMD recordsbetween editor andMetaiS.First testing scenario was passed using CatMDEdit without anysystemandfunctionalconstraint.CreatedMDrecordwasexportedto ISO 19115/19139 XML file and uploaded to GeoNetworkdatabase–preparedfordiscoveryviatheweb.TheGeoNetworkprovidesapowerful tool for the implementationofallcomponentsofMIGI,andtheapplicationenvironmentismorethanuser-friendly.Itofferswell-arrangedMDmanagement,whichprovidesfortheircreationdirectlythroughthewebinterface,theirdistributionwithimportsandexports,theirdisplayandfinallytheirdiscovery.ItusesCSWtocommunicatewithremoteGeocatalogues.Thesystem is incompliancewith the fundamentalsofdistributeddiscovery.Using this system is particularly beneficial in buildingcomponents ofMIGI.MD records from testing scenario 1 and 2were uploaded to themetadata catalogue ofGeoNetworkwithoutany constraints. First part of scenario 3 was passed and systemappearedimportedMDrecordsaftersearchingperformance.gvSIG is adesktop GIS tool, which in addition to agreatfunctionality in the field of GD allows MD discovery from theremote Geocatalogues (tested only from GeoNetwork). The user

Fig. 8 A new GUI of GeoNetwork localized to the Slovak environment

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RefeRences

• Kliment, T. (2009):Metainformationinfrastructureforspatialinformation.Writtenpartofdissertationexamination.DepartmentofTheoreticalGeodesy, Faculty ofCivil Engineering, SlovakUniversityofTechnology,Bratislava

• Nogueras-Iso, J. et al. (2005):GeographicInformationMetadataforSpatialDataInfrastructures-Resources,InteroperabilityandInformationRetrieval.SpringerVerlag

• Ožana, R. (2007): Evaluation of GeoNetwork OpensourceFeatures and Suitability for National Metaportal Design.GeoinformaticsInstitute,VŠB–TUOstrava

• Directive (2007): Directive 2007/2/EC of the EuropeanParliament andof theCouncil of14March2007establishingan Infrastructure for Spatial Information in the EuropeanCommunity(INSPIRE)

• FGDC (1998):Contentstandardfordigitalgeospatialmetadata,Document FGDC-STD-001-1998. Federal Geographic DataCommittee(FGDC),MetadataadhocWorkingGroup.

• ISO (2003): ISO 19115:2003 – Geographic information –Metadata.ISO,Switzerland,2003

• ISO (2005):ISO19128:2005-Geographicinformation-Webmapserverinterface,ISO,Switzerland,2005

• ISO (2007a): ISO/TS 19139:2007 - Geographic information –Metadata–XMLschemaimplementation,ISO,Switzerland,2007

• ISO (2007b): ISO 19136:2007 - Geographic information -GeographyMarkupLanguage(GML),ISO,Switzerland,2007

• ISO (2009):ISO15836:2009-Informationanddocumentation-TheDublinCoremetadataelementset.ISO,Switzerland,2009

• OGC (2005):WebFeatureServiceImplementationSpecification,v.3.2.1,OGC04-094,OpenGeospatialConsortium,2005

• OGC (2006): OpenGIS® Web Map Server ImplementationSpecification, v. 1.3.0, OGC OGC 06-042, Open GeospatialConsortium,2006

• OGC (2007a):OpenGIS®CatalogueServicesSpecification,v.2.0.2,OGC07-006r1,OpenGeospatialConsortium,2007

• OGC (2007b): OpenGIS® Geography Markup Language(GML) Encoding Standard, v. 3.2.1, OGC 07-036, OpenGeospatialConsortium,2007

can retrieve the location of geospatial sources investigating theMD records content through CSW.After that the user can view,download, process etc., these data.This desktopGIS tool can beusedas thediscoveryclientwithin the infrastructure.Secondpartof scenario 3 was passed and tool appeared MD records fromGeoNetworkaftersearchingperformancewithingvSIGGUI.deegree CSW introduces asolution for CSW implementation. Itdoes no provide user-friendly GUI for communication with theservice(discoveryandmanagementofMDrecords)currently.TheinstallationismorecomplicatedthaninGeoNetwork.Itisnecessaryto install the servlet and thenDBMS separately. Finally, one canconfigure the service via aset ofXML type files.By eliminatingthese„shortcomings“anddevelopinganoptimaluser-friendlyGUIfortheend-userthisarchitecturecanbeclassifiedasapowerfultoolforimplementingthecomponentsofMIGIintopractice.

5 conclusion anD future WorK

Thepaperprovidessummaryofauthorsknowledgegainedduringthe first stageofdoctoral study finishedbyhisdissertationexam.Themainobjectiveof the topic,whichhasbeendescribedwithinthispaper,ismetainformationaboutgeospatialresourcesretrieval.

Metainformation is the result of the MD content investigation.In order to deliver the MD to the end user, their workflowconsists from alarge number of procedures, from their creation,storage, distribution and implementation through the environmentof infrastructure. This infrastructure must allow the user todiscover and retrieve MD. This environment can be defined asMetainformationInfrastructureforGeospatialInformation,whichispartofInfrastructureforGeospatialinformation,whichdealswithmetainformation.Foritsimplementationintopracticeopensourcetoolscanbeused,becausetheyareusuallyfreeandofferanopensource code. It is possible to install, test andmodify these tools,according to thespecificneeds.The resultsachieved in (Kliment,2009)andsummarizedinthispaperdescribetheadvantagesoftheimplementationoftheseopensourcetoolsintopracticeforbuildingaNational Infrastructure forGeospatial Information in theSlovakRepublicforitsnearfutureconnectiontoINSPIRE.For the future work author would like propose and implementreference Geocatalogue solution for Geodesy and Cartographydomain with all requirements arising from European legislation(Directive, 2007) and following standardization in technical andsemanticlevel.

This contribution has been made thanks to VEGA No. 1/4025/07.

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