毕业设计论文外文文献翻译.docx

毕业设计论文外文文献翻译.docx

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毕业设计论文外文文献翻译

南京航空航天大学金城学院

毕业设计（论文）外文文献翻译

系部

软件工程

专业

计算机科学与技术

学生姓名

蒋晨

学号

2012022113

指导教师

李海林

职称

讲师

2016年4月

EnvironmentalModelling&Software

1.Introduction

OverthelastdecadestheamountofgeospatialdatahasgrownrapidlyasaresultofthenumberofsatellitesandtheuseofGlobalPositioningSystems（GPS）.Toassistintheanalysisandvisualizationofallthisdata,severalgeographicinformationsystems（GISs）andWebGISsiteshavebeendeveloped（SteinigerandHunter,2012）.SomeoftheWebGISsitessharecommonfunctionalities,suchasaccesstorawdataortheabilitytooverlapdifferentlayers（Kulawiaketal.,2010;Karnataketal.,2012;NairandKatiyar,2011）.WebGISsitesthatdisplayenvironmentaldata,likethePacificIslandsOceanObservingSystem（Voyager）ortheWebGISsitesdevelopedbytheEuropeanEnvironmentAgency,haveanevenlargersetofcommonfeatures,suchastheabilitytoidentifylayerdataatanycoordinate,andthecapabilitytoplotdatainrealtime.However,tothebestofourknowledge,anyopensourceprogramthatautomaticallygeneratesWebGISsiteswithaminimumsetoffeaturesthatallowefficientpublicationof4Dgeospatialdata.

AcommonprocedureforpublishinggeoreferenceddataonaWebGISsiteincludesthefollowingsteps.First,generatethedatatobepublished.Then,uploadthedataintoamapserversuchasMapServer（Kropla,2005）,GeoServer（Deoliveira,2008）,ArcMapServer,ncWMS（Bloweretal.,2013）,etc.Finally,withagroupofprogrammersandwebdesigners,buildthewebinterface（theWebGISsite）todisplaythedatafortheuser.Thisinterfaceprovidesseveralwaystovisualizeandservedata,and,evenwhenmostWebGISsitesdonothavedirectaccesstothedata,theynormallyobtainthedatathroughmapsevers.Thesoftwaredescribedinthispapergreatlysimplifiesthefinalstep,buildingWebGISsites,thusreducingthetimeandcostsforpublishinggeospatialdataontheweb.

FreeandOpenSourceSoftware（FOSS）thathelpsbuildingWebGISsitesalreadyexists.Fig.1,adaptedfromSteinigerandHunter（2013）,showstheFOSSGISsoftwarethatisavailabletoaidpublishinggeographicdataonthewebatanyofthepreviouslydiscussedsteps.ThesoftwareintheDesktopGIScategoryareprogramsthatrunonpersonalcomputersandareabletodisplay,query,update,andanalyzegeographicdata.QuantumGIS（ShekharandXiong,2007）andGRASS（Neteleretal.,2012）aretwoofthemostmatureFOSSdesktopGISprograms.Thesetwoprogramscanaccomplishamultitudeoftasksandhavebeenusedtoprepareandanalyzeenvironmentaldataforseveralprojects（Gkatzofliasetal.,2013;Grinandetal.,2013）.

TheWebMapServerscategoryaccommodatessoftwarethatprovidesseveraloptionstoaccessandvisualizegeoreferenceddatathroughstandardsoftheOpenGeospatialConsortium（WebMappingServices（WMS）（delaBeaujardiere,2006）,WebFeatureServices（WFS）（Vretanos,2005）,andWebCoverageServices（WCS）（Baumann,2010））.Thetwobest-knownwebmapserversareMapServerandGeoServer,bothofthemoffervectorandrastersupportandhavecomparablefunctionalitytosimilarproprietarysoftware（SteinigerandHunter,2013）.

Fig.1.Simplifiedschemeofthefreeandopensourcegeographicinformationsoftwarefortheweb.Adaptedfrom.SteinigerandHunter（2013）.

Anotherwebmapserver,thatisworthmentioningfortheenvironmentalmodelingcommunity,isthencWMSwhichhastheparticularfeatureofbeingabletoserve4DdatastoredasNetCDFfiles,awidelyusedfileformatforstoringenvironmentalmodeldatasets（RewandDavis,1990）.TheDEFENSE（Tirantietal.,2014）,andtheinteractivevisualizationsystembyKulawiaketal.（2010）aresomeexamplesofenvironmentaldecisionsupportsystemsthatuseFOSSwebmapservers.

TheWebGISlibrariesandtheWebMapDevelopmentFrameworksaretwocategoriesthatencompassGISsoftwareusedtobuildthefinalinterfacetodisplaygeographicdataasdynamicmapsontheweb.ThewebGISlibrariesareapplicationprogramminginterfaces（API's）forthevisualizationandmanipulationofspatialdatathatimplementtheWMS,WFS,etc.OpenLayers（Hazzard,2011）isoneofthemostextensivelibrariesinthiscategory,itisimplementedinJavaScript.Finally,thesoftwareintheWebMapDevelopmentFrameworkscategory,contributewithtoolsforcreatingadvancedwebapplications.TheseframeworksusethewebGISlibrariesandcontaintoolsforthemanagementoflayers,menus,andthemesoftheWebGISsites.SomewellknownprogramsinthiscategoryareMapbender3（http:

//mapbender3.org/）,GeoMajas（http:

//www.geomajas.org/）,MapFish（http:

//www.mapfish.org/）andGeoMOOSE（http:

//www.geomoose.org/）.OWGISbelongstothislastcategoryasitgivesaneasywaytodevelopWebGISsitesthroughtheconfigurationofXMLfiles.ThemainfeaturethatdifferentiatesOWGISfromtherestofthedevelopmentframeworksisthesetoftoolsthatOWGISprovidestovisualize4Ddatathroughtheweb.

OWGIS（http:

//owgis.org/）,originallyOpenWebGIS,isanopensourcesoftwarethatcreatesself-containedWebGISsiteswithcommonfeaturesusedbythescientificcommunity.OWGISisaJavawebapplicationthatgenerateswebsitesbyautomaticallywritingHTMLandJavaScriptcode.ThewebsitesbuiltwithOWGISareconfiguredbyXMLfilesandcanaccommodatemapswithlayersservedthroughanymapserver,suchasGeoServer,thatcomplieswiththeWMSstandard.OWGISisalsocapableofconstructingWebGISsitesthatdisplay3DdataservedbytheTHREDDSservers（Domenicoetal.,2006）orthencWMSservers,usingtheWMSextensionproposedbyBloweretal.（2013）.

ThecurrentfeaturesthatOWGISprovidesonthegeneratedWebGISsitesare:

multiplelanguages,animations,mobileinterface,ContextualQueryLanguage（CQL）filtering（http:

//en.wikipedia.org/wiki/Contextual_Query_Language）,identifyfeatures,theabilitytodownloaddataasKML,GeoTIFForshapefiles,andthecapacitytoplotverticalprofilesandverticaltransectsatdifferentlocations.ThoughsomeofthesefeaturesarealreadyavailableinmanyWebGISsites,regardlessofwhetherornottheydisplayscientificdataorothertypesofgeographicdata,OWGISallowsbuildingandmaintainingnewsiteswithallthesefeaturesbysimplyeditingXMLfiles.

OWGISisbeingdevelopedattheCenterforOcean-AtmosphericPredictionStudies（COAPS）,FloridaStateUniversity（FSU）,incollaborationwiththeUniversidadNacionalAutonomadeMexico（UNAM）.OWGISiscurrentlyusedastheinteractivevisualizationmapoftheDigitalClimaticAtlasofMexico（Zavala-Hidalgoetal.,2010）,whichhasbeenavailablesince2009andprovidesaccesstomorethan2000layersofoceanicclimate,climatechangescenarios,bioclimaticparameters,andsocioeconomicindicators,amongothervariables.OWGISisalsousedbytheDeep-CConsortium（http:

//deep-c.org/）todisplayoceanographicdatafromtheGulfofMexico.

Thepaperisorganizedasfollows.Section2describesthearchitectureofOWGISandthedesignprinciplesthatitfollowswhencreatingwebsites.Section3explainshowtoconfigureOWGISfornewapplications.Section4illustratesthecurrentfeaturesprovidedbyOWGIS.Section5describesaspecificcasestudywhereOWGISissuccessfullyusedtodisplayoceandatafromtheGulfofMexico.Section6endswithadiscussiononthepresentedsoftwareandoutlinessomefuturefunctionalityofOWGIS.

2.Architecture

LikeotherJavawebapplications,OWGIScanbecontainedinawebarchive（WAR）filethatcanbedeployedinanyservletcontainer,suchasApacheTomcat.Similartoacommonwebapplication,OWGIScreateswebcontent,JavaScript,andHTML;howeverwithOWGIS,thefinalwebsitesareself-containedWebGISsites.TheJavaScriptcodegeneratedbyOWGISusesOpenLayers（http:

//openlayers.org/）,anopensourcelibraryforcreatingdynamicmaps.OWGISalsocreatescustomJavaScriptcodeforrequestingdatafromserversthatcomplywiththeWMSandWFSstandards.

OWGIS-createdwebsitesdisplaylayersthatareservedthroughmapservers.Theinformationabouteachlayer,suchasthenameofthelayer,isconfiguredusingXMLfiles.ThesefilesareusedtomodifythelookandcontentoftheOWGISsitesandaredescribedinSection3.OWGISmonitorsanychangestothesefiles,madebytheadministrators,andisabletoupdatewebsiteswithoutreloadingthewebapplicationontheserver.Thisfeatureisveryusefulwhenthedatabeingdisplayedonthemapismodifiedoften.Fig.2showsasimplediagramoftheprocessusedbyOWGIStogeneratewebcontentfortheuser.

WhenausermakesanewHTMLrequest,OWGISverifiesthathavebeennomodificationstotheXMLconfigurationfiles.Iftherehavebeenanychanges,OWGISparsesalltheinformationintheXMLfilesandrebuildsinternaldatastructuresforthesites.Oncetheinformationisstoredinternally,OWGISusesittobuildthedesiredinterface,takingintoaccountthespecificuserrequest.

TheOWGISsourcecodeisdividedinfourgeneralmodules:

model,business,servlets,andtools.ThemodelmodulestoresallthelayersobtainedfromtheXMLfilesaswellasthemenusinasetofdatastructures.Theservletsmodulecontainsalltheservlets,whichareinchargeofreceivingnewrequestsfromtheuserandredirectingeachrequesttothepropermethodinthebusinessmodule.TheservletsmodulealsosendscustomizedJavaScriptcodetotheuser.Thebusinessmoduleisinchargeofreadingthecurrentuser'sconfigurationandthedataofthemodelmoduletobuildtheproperJavaScriptcodefortheuser.Thetoolsmodulecontainsanumberofstaticfunctionsusedtocreatewebcontent.

2.1.Designprinciples

Fig.2.SimplifiedschemeofOWG